Federal Register, Volume 77 Issue 117 (Monday, June 18, 2012)

[Federal Register Volume 77, Number 117 (Monday, June 18, 2012)]
[Rules and Regulations]
[Pages 36341-36386]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-13828]

[[Page 36341]]

Vol. 77

Monday,

No. 117

June 18, 2012

Part II

Environmental Protection Agency

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40 CFR Parts 87 and 1068

Control of Air Pollution From Aircraft and Aircraft Engines; Emission
Standards and Test Procedures; Final Rule

Federal Register / Vol. 77 , No. 117 / Monday, June 18, 2012 / Rules
and Regulations

[[Page 36342]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 87 and 1068

[EPA-HQ-OAR-2010-0687; FRL-9678-1]
RIN 2060-AO70

Control of Air Pollution From Aircraft and Aircraft Engines;
Emission Standards and Test Procedures

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: EPA is adopting several new aircraft engine emission standards
for oxides of nitrogen (NOX), compliance flexibilities, and
other regulatory requirements for aircraft turbofan or turbojet engines
with rated thrusts greater than 26.7 kilonewtons (kN). We also are
adopting certain other requirements for gas turbine engines that are
subject to exhaust emission standards as follows. First, we are
clarifying when the emission characteristics of a new turbofan or
turbojet engine model have become different enough from its existing
parent engine design that it must conform to the most current emission
standards. Second, we are establishing a new reporting requirement for
manufacturers of gas turbine engines that are subject to any exhaust
emission standard to provide us with timely and consistent emission-
related information. Third, and finally, we are establishing amendments
to aircraft engine test and emissions measurement procedures. EPA
actively participated in the United Nations' International Civil
Aviation Organization (ICAO) proceedings in which most of these
requirements were first developed. These regulatory requirements have
largely been adopted or are actively under consideration by its member
states. By adopting such similar standards, therefore, the United
States maintains consistency with these international efforts.

DATES: These final rules are effective on July 18, 2012. The
incorporation by reference of certain publications listed in this
regulation is approved by the Director of the Federal Register as of
July 18, 2012.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2010-0687. All documents in the docket are listed on the
http://www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, e.g., confidential business
information or other information whose disclosure is restricted by
statute. Certain other material, such as copyrighted material, is not
placed on the Internet and will be publicly available only in hard copy
form. Publicly available docket materials are available electronically
through http://www.regulations.gov or in hard copy at the EPA Docket
Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave. NW.,
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30
p.m., Monday through Friday, excluding legal holidays. The telephone
number for the Public Reading Room is (202) 566-1744, and the telephone
number for the Air Docket is 202-566-1742.

FOR FURTHER INFORMATION CONTACT: Richard Wilcox, Office of
Transportation and Air Quality, Office of Air and Radiation,
Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI
48105; telephone number: (734) 214-4390; fax number: (734) 214-4816;
email address: wilcox.rich@epa.gov.

SUPPLEMENTARY INFORMATION:

Does this action apply to me?

Entities potentially regulated by this action are those that
manufacture and sell aircraft engines and aircraft in the United
States. Regulated categories include:

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Examples of potentially
Category NAICS \a\ Codes SIC \b\ Codes affected entities
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Industry................................... 336412 3724 Manufacturers of new aircraft
engines.
Industry................................... 336411 3721 Manufacturers of new
aircraft.
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\a\ North American Industry Classification System (NAICS).
\b\ Standard Industrial Classification (SIC) system code.

This table lists the types of entities that EPA is now aware could
potentially be regulated by this action. Other types of entities not
listed in the table could also be regulated. To determine whether your
activities are regulated by this action, you should carefully examine
the applicability criteria in 40 CFR 87.1 (part 87). If you have any
questions regarding the applicability of this action to a particular
entity, consult the person listed in the preceding FOR FURTHER
INFORMATION CONTACT section.

Table of Contents

I. Executive Summary
II. Overview and Background
A. Contents of the Final Rule
B. EPA's Authority and Responsibilities Under the Clean Air Act
C. Interaction With the International Community
D. Brief History of EPA's Regulation of Aircraft Engine
Emissions
E. Brief History of ICAO Regulation of Aircraft Engine Emissions
III. Why is EPA taking this action?
A. Inventory Contribution
B. Health, Environmental and Air Quality Impacts
1. Background on Ozone, PM and NOX
a. What is ozone?
b. What is particulate matter?
c. What is NOX?
2. Health Effects Associated With Exposure to Ozone, PM and
NOX
a. What are the health effects of ozone?
b. What are the health effects of PM?
c. What are the health effects of NOX?
3. Environmental Effects Associated With Exposure to Ozone, PM
and NOX
a. Deposition of Nitrogen
b. Visibility Effects
c. Plant and Ecosystem Effects of Ozone
4. Impacts on Ambient Air Quality
IV. Details of the Final Rule
A. NOX Standards for Newly-Certified Engines
1. Tier 6 NOX Standards for Newly-Certified Engines
a. Numerical Emission Limits for Higher Thrust Engines
b. Numerical Emission Limits for Lower Thrust Engines
2. Tier 8 NOX Standards for Newly-Certified Engines
a. Numerical Emission Limits for Higher Thrust Engines
b. Numerical Emission Limits for Lower Thrust Engines
B. Application of NOX Standards for Newly-
Manufactured Engines
1. Phase-In of the Tier 6 NOX Standards for Newly-
Manufactured Engines
2. Carryover of Previously Generated Emission Data
3. Exemptions and Exceptions From the Tier 6 Production Cutoff
a. New Provisions for Spare Engines
b. New Provisions for Engines Installed in New Aircraft
i. Time-Frame and Scope
ii. Production Limit
iii. Exemption Requests
iv. Coordination of Exemption Requests
v. Low-Volume, Time-Limited Transitional Exception Program
c. Voluntary Emission Offsets
4. Potential Phase-In of New Tier 8 NOX Standards for
Newly-Manufactured Engines

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C. Application of Standards for Derivative Engines
D. Annual Reporting Requirement
E. Standards for Supersonic Aircraft Turbine Engines
F. Amendments to Test and Measurement Procedures
G. Possible Future Revisions to Emission Standards for New
Technology Turbine Engines and Supersonic Aircraft Turbine Engines
V. Description of Other Revisions to the Regulatory Text
A. Applicability Issues
1. Military Engines
2. Noncommercial Engines
B. Non-Substantive Revisions
C. Clarifying Language for Regulatory Text
VI. Technical Feasibility and Cost Impacts
VII. Consultation With FAA
VIII. Public Participation
IX. Statutory Provisions and Legal Authority
X. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review, and
Executive Order 13563: Improving Regulation and Regulatory Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Analysis
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health & Safety Risks
H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
I. National Technology Transfer Advancement Act
J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low Income
Populations
K. Congressional Review Act
L. Executive Order 13609: Promoting International Regulatory
Cooperation

I. Executive Summary

A. Purpose of the Regulatory Action

The primary purpose of this rule is to adopt new oxides of nitrogen
(NOX) emission standards for aircraft engines with rated
thrusts greater than 26.7 kN thrust. These are mostly commercial
passenger and freighter aircraft in common use at airports across the
U.S. It does not include engines used on military aircraft.
NOX is strongly correlated with NO2, for which
EPA has established National Ambient Air Quality Standards (NAAQS),
i.e., a criteria pollutant, and it is an important precursor gas in the
formation of tropospheric ozone and secondary particulate matter which
are common air pollutants in urban areas where airports are located.
Currently, approximately 154 million people live in areas designated
nonattainment for one or more of the current NAAQS. This rule will
allow us to enforce in the U.S. the emission standards adopted by ICAO,
and will be useful to states in attaining or maintaining the ozone,
PM2.5, and NO2 NAAQS standards. This rule also
contains several provisions to facilitate the implementation of EPA's
aircraft engine emission regulations and related requirements. It is
also important to note that adoption of the provisions in this rule
meets U.S. treaty obligations under the Chicago Convention of 1944 by
aligning our regulations with those in the International Civil Aviation
Organization Annex 16, Volume II (adopted in 2010) that the U.S. helped
to develop and support as part of the international process. This rule
is being implemented under the authority provided in section 231 of the
Clean Air Act (42 U.S.C. 7571), which directs the Administrator of EPA
to, from time to time, propose aircraft engine emission standards
applicable to the emission of any air pollutant from classes of
aircraft engines which in her judgment causes or contributes to air
pollution that may reasonably be anticipated to endanger public health
or welfare.

B. Summary of Major Provisions of the Regulatory Action

The rule contains six major provisions. The first two provisions
are new NOX emission standards for newly certified-engine
models. The first standards, Tier 6, take effect when this rule becomes
effective. These represent approximately a 12 percent reduction from
current Tier 4 levels. They were actually adopted by ICAO in 2005 with
an implementation date in 2008. The second standards, Tier 8, were
adopted by ICAO in 2008 and take effect in 2014. These represent
approximately a 15 percent reduction from Tier 6 levels. As noted
above, both tiers of emission standards are needed to address local air
quality concerns (NAAQS) and to meet U.S. treaty obligations under the
Chicago Convention. The third major provision is a production cut-off
for newly-manufactured engines (as opposed to newly-certified engines)
which basically requires that after December 31, 2012 all newly-
manufactured engines must meet at least Tier 6 NOX emission
standards. This is also needed to meet our obligations under the
Chicago Convention. The production cut-off is needed to ensure that the
emission reductions envisioned by the emission standards are achieved
on new production engines. The fourth major provision is related to
potential exemptions or exceptions to the production cut-off
requirement. These include revised provisions allowing manufacturers to
request that FAA in consultation with EPA grant exemptions from the
production cut-off for a designated number of engines within a
prescribed time frame. These also include a low-volume, time-limited
exception provision that will exclude several engines from the
production cutoff. Both of these provisions help to assure an orderly
transition to the new standards for engines needing more time to comply
or for a few engines at the end of their production life. Finally, the
rule includes a set of provisions which may be considered as minor if
viewed separately, but collectively are important in upgrading EPA's
regulations by incorporating some related agreements from our ICAO
process and clarifying and improving existing provisions. Examples of
this include special provisions for spare engines, provisions related
to derivative engine models, test procedure specifications and
reporting requirements. These changes are important for an effective
implementation of the new requirements, and in many cases are also
needed to meet our obligations under the Chicago Convention.

C. Costs and Benefits

This is not an economically significant regulatory action. Aircraft
engines are international commodities used on aircraft manufactured and
sold around the world. When developing new engine models manufacturers
not only consider current emission requirements but also try to
anticipate the stringency of future standards and respond
appropriately. Engine manufacturers participated in the deliberations
leading up to ICAO decisions on the aircraft engine NOX
emission standards and after the ICAO decisions they incorporated
engine technology changes as needed to meet the new ICAO requirements.
This helps to ensure the world wide acceptability of their products.
Essentially all of these changes are now complete. Thus, while there is
some cost to a manufacturer for responding to the new ICAO provisions,
there is no significant further direct cost to the manufacturers
created by EPA's adopting the requirements into U.S regulations. In
fact, it is likely that our adopting these requirements facilitates the
acceptance of U.S. type certificates by aircraft manufacturers and
airlines around the world.

II. Overview and Background

This section summarizes the major provisions of the final rule for
aircraft gas turbine engines. It also contains

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background on the EPA's standard setting authority and responsibilities
under the Clean Air Act, the connection between our emission standards
and those of the international community, and a brief regulatory
history for this source of emissions.

A. Contents of the Final Rule

We are adopting several new emission standards and other regulatory
requirements for aircraft turbofan and turbojet engines \1\ with rated
thrusts greater than 26.7 kilonewtons (kN). First, we are establishing
two new tiers of more stringent emission standards for oxides of
nitrogen (NOX).\2\ The standards apply differently to two
classes of these engines, i.e., ``newly-certified engines'' and
``newly-manufactured engines.'' The newly-certified engine standards
apply to aircraft engines that have received a new type certificate and
have never been manufactured prior to the effective date of the new
emission standards. Requirements for newly-manufactured engines apply
to aircraft engines that were previously certified and manufactured in
compliance with preexisting standards, and they require manufacturers
to either comply with the newer standards by a specified future date or
cease production of the affected engine models. Newly-manufactured
engine standards are also sometimes referred to as ``production
cutoff'' standards. Second, we are adopting certain time-limited
flexibilities, i.e., the potential for exemptions or exceptions as
defined in the regulations for newly-manufactured engines that may not
be able to comply with the first tier of the NOX standards
because of specific technical or economic reasons.\3\
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\1\ Turbofan and turbojet engines will be collectively referred
to as turbofan engines hereafter for convenience.
\2\ As previously mentioned, these new NOX standards
are identical to requirements established by ICAO. The stringency of
any new emission standard is selected based on an assessment of the
technical feasibility, cost, and environmental benefit of potential
requirements. The NOX standards we are promulgating today
will not affect fuel economy or have any practical effect on
CO2 emissions. (See International Civil Aviation
Organization (ICAO), ``Committee on Aviation Environmental
Protection (CAEP), Eighth Meeting, Montreal, 1 to 12 February 2010,
CAEP/8 NOX Stringency Cost-Benefit Analysis Demonstration
Using APMT-IMPACTS,'' CAEP/8-IP/30, December 1, 2010. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.)
\3\ These exemption or exception provisions are conceptually the
same as the ICAO exemption provisions and provide the same
regulatory flexibilities to all engine manufacturers.
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We are also making a number of additional changes that would apply
to a wider range of aircraft gas turbine engines \4\ than those that
would be subject to the new emission standards.\5\ First, we are
defining the meaning of a derivative engine for emissions certification
purposes. The intent of this definition is to distinguish when the
emission characteristics of a new turbofan engine model vary
sufficiently from its existing parent engine design, and must show
compliance with the emission standard for a newly-certificated engine.
Second, we are establishing new reporting requirements for
manufacturers that produce gas turbine engines subject to any exhaust
emission standard. This will provide us with timely and consistent
emission data and other information that is necessary to conduct
emission inventory and air quality analyses and develop appropriate
public policy for the aviation sector. Specifically, reports are
required for turbofan engines with rated thrusts greater than 26.7 kN,
which are subject to gaseous emission and smoke standards, in addition
to turbofans less than or equal to 26.7 kN, and all turboprop engines,
that are only subject to smoke standards.\6\ Third, we are adopting
minor amendments to the test and measurement procedures for aircraft
engines. Finally, as described in section IV, we are making minor
amendments to regulator provisions addressing definitions, acronyms and
abbreviations, general applicability and requirements, exemptions, and
incorporation by reference.
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\4\ The term gas turbine engine includes turbofan, turbojet, and
turboprop engines designs. The rated output for turbofan and
turbojet engines is normally expressed as kilonewtons (kN) thrust.
The rated output for turboprop engines is normally expressed as
shaft horsepower (hp) or shaft kilowatt (kW).
\5\ This includes turbofan and turbojet engines less than 26.7
kN thrust and all turboprop engines that are subject to any emission
standard, e.g., smoke.
\6\ As discussed further in section III.D., the voluntary
emission data report to ICAO does not include turbofans at or below
26.7 kN or turboprops subject to any emission standard.
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Most of these new regulatory requirements have already been adopted
by the United Nation's International Civil Aviation Organization
(ICAO). The requirements contained in this final rule bring the United
States into alignment with the international standards and recommended
practices.

B. EPA's Authority and Responsibilities Under the Clean Air Act

Section 231(a)(2)(A) of the Clean Air Act (CAA) directs the
Administrator of EPA to, from time to time, propose aircraft engine
emission standards applicable to the emission of any air pollutant from
classes of aircraft engines which in her judgment causes or contributes
to air pollution that may reasonably be anticipated to endanger public
health or welfare. (See 42 U.S.C. 7571(a)(2)(A).) Section 231(a)(2)(B)
directs EPA to consult with the Administrator of the Federal Aviation
Administration (FAA) on such standards, and prohibits EPA from changing
aircraft emission standards if such a change would significantly
increase noise and adversely affect safety. 42 U.S.C. 7571(a)(2)(B)(i)-
(ii). Section 231(a)(3) provides that after we propose standards, the
Administrator shall issue such standards ``with such modifications as
he deems appropriate.'' 42 U.S.C. 7571(a)(3). The U.S. Court of Appeals
for the D.C. Circuit has held that this provision confers an unusually
broad degree of discretion on EPA to adopt aircraft engine emission
standards as the Agency determines are reasonable. NACAA v. EPA, 489
F.3d 1221 (D.C. Cir. 2007).
In addition, under CAA section 231(b) EPA is required to ensure, in
consultation with the U.S. Department of Transportation (DOT), that the
effective date of any standard provides the necessary time to permit
the development and application of the requisite technology, giving
appropriate consideration to the cost of compliance. 42 U.S.C. 7571(b).
Section 232 then directs the FAA to prescribe regulations to ensure
compliance with EPA's standards. 42 U.S.C. 7572. Finally, section 233
of the CAA vests the authority to promulgate emission standards for
aircraft or aircraft engines only in EPA. States are preempted from
adopting or enforcing any standard respecting aircraft engine emissions
unless such standard is identical to EPA's standards. 42 U.S.C. Sec.
7573. Section VI of today's final rule further discusses our
coordination with DOT through the FAA.\7\ It also describes DOT's
responsibility under the CAA to enforce the aircraft emission standards
established by EPA.
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\7\ The functions of the Secretary of Transportation under part
B of title II of the Clean Air Act (Sec. Sec. 231-234, 42 U.S.C.
7571-7574) have been delegated to the Administrator of the FAA. 49
CFR 1.47(g).
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C. Interaction With the International Community

We began regulating the air pollution emissions from aircraft
engines in 1973. Since that time, we have worked with the FAA and later
with the International Civil Aviation Organization (ICAO) to develop
international standards and other recommended practices pertaining to
aircraft engine emissions. ICAO was established in 1944 by the United
Nations (by the Convention on International Civil Aviation, the

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``Chicago Convention'') ``* * * in order that international civil
aviation may be developed in a safe and orderly manner and that
international air transport services may be established on the basis of
equality of opportunity and operated soundly and economically.'' \8\
ICAO's responsibilities include developing aircraft technical and
operating standards, recommending practices, and generally fostering
the growth of international civil aviation. The United States is
currently one of 191 participating member States of
ICAO.^{9 10}
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\8\ ICAO, ``Convention on International Civil Aviation,'' Ninth
Edition, Document 7300/9, 2006. Copies of this document can be
obtained from the ICAO Web site located at www.icao.int.
\9\ Members of ICAO's Assembly are generally termed member
States or contracting States. These terms are used interchangeably
throughout this preamble.
\10\ There are currently 191 Contracting States according to
ICAO Web site located at www.icao.int.
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In the interests of global harmonization and international air
commerce, the Chicago Convention urges a high degree of uniformity by
its member States. Nonetheless, the Convention also recognizes that
member States may adopt their own unique airworthiness standards and
that some may adopt standards that are more stringent than those agreed
upon by ICAO.
The Convention has a number of other features that govern
international commerce. First, States that wish to use aircraft in
international transportation must adopt emission standards and other
recommended practices that are at least as stringent as ICAO's
standards. States may ban the use of any aircraft within their airspace
that does not meet ICAO standards.\11\ Second, States are required to
recognize the airworthiness certificates of any State whose standards
are at least as stringent as ICAO's standards, thereby assuring that
aircraft of any member State will be permitted to operate in any other
member State.\12\ Third, and finally, to ensure that international
commerce is not unreasonably constrained, a participating nation which
elects to adopt more stringent standards is obligated to notify ICAO of
the differences between its standards and ICAO standards.\13\ However,
if a nation sets tighter standards than ICAO, air carriers not based in
that nation would only be required to comply with ICAO standards or
more stringent standards imposed by their own nations, if applicable.
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\11\ ICAO, ``Convention on International Civil Aviation,''
Article 87, Ninth Edition, Document 7300/9, 2006. Copies of this
document can be obtained from the ICAO Web site located at
www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf.
\12\ ICAO, ``Convention on International Civil Aviation,''
Article 33, Ninth Edition, Document 7300/9, 2006. Copies of this
document can be obtained from the ICAO Web site located at
www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf.
\13\ ICAO, ``Convention on International Civil Aviation,''
Articles 38, Ninth Edition, Document 7300/9, 2006. Copies of this
document can be obtained from the ICAO Web site located at
www.icao.int/icaonet/arch/doc/7300/7300_9ed.pdf.
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ICAO's Committee on Aviation Environmental Protection (CAEP)
undertakes ICAO's technical work in the environmental field. The
Committee is responsible for evaluating, researching, and recommending
measures to the ICAO Council that address the environmental impact of
international civil aviation. CAEP is composed of various task groups,
work groups, and other committees whose contributing members include
atmospheric, economic, aviation, environmental, and other professionals
interested in aviation and environmental protection. At CAEP meetings,
the United States is represented by the FAA, which plays an active role
at these meetings.\14\ EPA has historically been a principal
participant in the development of U.S. policy in various ICAO/CAEP
working groups and other international venues, assisting and advising
FAA on aviation emissions, technology, and policy matters. If ICAO
adopts a CAEP proposal for a new environmental standard, it then
becomes part of ICAO standards and recommended practices (Annex 16 to
the Chicago Convention).^{15 16}
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\14\ Pursuant to the President's memorandum of August 11, 1960
(and related Executive Order No. 10883 from 1960), the Interagency
Group on International Aviation (IGIA) was established to facilitate
coordinated recommendations to the Secretary of State on issues
pertaining to international aviation. The DOT/FAA is the chair of
IGIA, and as such, the FAA represents the U.S. on environmental
matters at CAEP.
\15\ ICAO, ``Aircraft Engine Emissions,'' International
Standards and Recommended Practices, Environmental Protection, Annex
16, Volume II, Second Edition, July 2008. A copy of this document is
in docket number EPA-HQ-OAR-2010-0687.
\16\ CAEP develops new emission standards based on an assessment
of the technical feasibility, cost, and environmental benefit of
potential requirements.
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D. Brief History of EPA's Regulation of Aircraft Engine Emissions

As mentioned above, we initially regulated gaseous exhaust
emissions, smoke, and fuel venting from aircraft engines in 1973.\17\
Since that time, we have occasionally revised those regulations. Two of
these revisions are most pertinent to today's final rule. First, in a
1997 rulemaking, we made our emission standards and test procedures
more consistent with those of ICAO for turbofan engines used in
commercial aviation with rated thrusts greater than 26.7kN.\18\ These
ICAO requirements are generally referred to as CAEP/2 standards. (The
numbering nomenclature for CAEP requirements is discussed in the next
section.) That action included new NOX emission standards
for newly-manufactured commercial turbofan engines (those engines built
after the effective date of the regulations that were already certified
to pre-existing standards) \19\ and for newly-certified commercial
turbofan engines (those engine models that received their initial type
certificate after the effective date of the regulations). It also
included a CO emission standard for newly-manufactured commercial
turbofan engines. Second, in our most recent rulemaking in 2005, we
promulgated more stringent NOX emission standards for newly-
certified commercial turbofan engines.\20\ That final rule brought the
U.S. standards closer to alignment with ICAO CAEP/4 requirements that
were effective in 2004. In ruling on a petition for judicial review of
the 2005 rule filed by the National Association of Clean Air Agencies
(NACAA), the U.S. Court of Appeals held that EPA's approach of tracking
the ICAO standards was reasonable and permissible under the CAA. NACAA
v. EPA, 489 F.3d 1221, 1230-32 (D.C. Cir. 2007).
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\17\ U.S. EPA, ``Emission Standards and Test Procedures for
Aircraft;'' Final Rule, 38 FR 19088, July 17, 1973.
\18\ U.S. EPA, ``Control of Air Pollution from Aircraft and
Aircraft Engines; Emission Standards and Test Procedures;'' Final
Rule, 62 FR 25356, May 8, 1997. While ICAO's standards were not
limited to ``commercial'' aircraft engines, our 1997 standards were
explicitly limited to commercial engines, as our finding that
NOX and CO emissions from aircraft engines cause or
contribute to air pollution which may reasonably be anticipated to
endanger public health or welfare was so limited, See 62 FR 25358.
As explained later in section IV.A.2. of today's notice, we are
expanding the scope of that finding and of our standards pursuant to
section 231(a)(2)(A) of the Clean Air Act to include such emissions
from both commercial and non-commercial aircraft engines based on
the physical and operational similarities between commercial and
noncommercial civilian aircraft and to bring our standards into full
alignment with ICAO's.
\19\ This does not mean that in 2005 we promulgated requirements
for the re-certification or retrofit of existing in-use engines.
\20\ U.S. EPA, ``Control of Air Pollution from Aircraft and
Aircraft Engines; Emission Standards and Test Procedures;'' Final
Rule, 70 FR 2521, November 17, 2005.
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E. Brief History of ICAO Regulation of Aircraft Engine Emissions

The first international standards and recommended practices for
aircraft engine emissions was recommended by CAEP's predecessor, the
Committee on Aircraft Engine Emissions (CAEE), and

[[Page 36346]]

adopted by ICAO in 1981.\21\ These standards limited aircraft engine
emissions of HC, CO, and NOX. In 1994, ICAO adopted a CAEP/2
proposal to tighten the original NOX standard by 20 percent
and amend the test procedures.\22\ At the next CAEP meeting (CAEP/3) in
1995, the Committee recommended a further tightening of 16 percent and
additional test procedure amendments, but in 1997 the ICAO Council
rejected this stringency proposal and approved only the test procedure
amendments. At the CAEP/4 meeting in 1998, the Committee adopted a
similar 16 percent NOX reduction proposal, which ICAO
approved on 1998. The CAEP/4 standards applied only to new engine
designs certified after December 31, 2003 (i.e., the requirements did
not also apply to previously certified, newly-manufactured engines
unlike the CAEP/2 standards). In 2004, CAEP/6 recommended a 12 percent
NOX reduction, which ICAO approved in 2005.^{23 24}
The CAEP/6 standards applied to new engine designs (newly-certified
models) certified after December 31, 2007. At the most recent meeting,
CAEP/8 recommended a further tightening of the NOX standards
by 15 percent for newly-certified engines.^{25 26} The
Committee also recommended that the CAEP/6 standards be applied to
newly-manufactured engines. ICAO approved these recommendations in
2011.\27\
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\21\ ICAO, Foreword of ``Aircraft Engine Emissions,''
International Standards and Recommended Practices, Environmental
Protection, Annex 16, Volume II, Third Edition, July 2008. Copies of
this document can be obtained from the ICAO Web site at
www.icao.int.
\22\ CAEP conducts its work over a period of years. Each work
cycle is numbered sequentially and that identifier is used to
differentiate the results from one CAEP to another by convention.
The first technical meeting on aircraft emission standards was
CAEP's successor, i.e., CAEE. The first meeting of CAEP, therefore,
is referred to as CAEP/2.
\23\ CAEP/5 did not address new aircraft engine emission
standards.
\24\ ICAO, ``Aircraft Engine Emissions,'' Annex 16, Volume II,
Third Edition, July 2008, Amendment 4 effective on July 20, 2008.
Copies of this document can be obtained from the ICAO Web site at
www.icao.int.
\25\ CAEP/7 did not address new aircraft engine emission
standards.
\26\ ICAO, ``Committee on Aviation Environmental Protection
(CAEP), Report of the Eighth Meeting, Montreal, February 1-12,
2010,'' CAEP/8-WP/80. A copy of this document is in docket number
EPA-HQ-OAR-2010-0687.
\27\ ICAO, ``Aircraft Engine Emissions,'' Annex 16, Volume II,
Third Edition, July 2008, Amendment 7 effective on July 18, 2011.
Copies of this document can be obtained from the ICAO Web site at
www.icao.int.
---------------------------------------------------------------------------

III. Why is EPA taking this action?

As mentioned above, section 231(a)(2)(A) of the CAA authorizes the
EPA Administrator to ``from time to time, issue proposed emission
standards applicable to the emission of any air pollution from any
class or classes of aircraft or aircraft engines which in his judgment
causes, or contributes to air pollution which may reasonably be
anticipated to endanger public health or welfare.'' 42 U.S.C.
7571(a)(2)(A).
One of the principal components of aircraft exhaust emissions is
NOX, a precursor to the formation of tropospheric ozone and
secondary PM.\28\ Most commercial airports are located in urbanized
areas \29\ and many urbanized areas have ambient pollutant levels above
the National Ambient Air Quality Standards (NAAQS) for ozone and fine
particulate matter (PM2.5) (i.e., they are in nonattainment
for ozone and PM2.5).\30\ This section discusses the
contribution of aircraft engines used in commercial service with rated
thrusts greater than 26.7kN to the national NOX emissions
inventory and to NOX emission inventories in selected ozone
and PM2.5 nonattainment areas, the potential effect of
NOX emissions in the upper atmosphere on ground level
PM2.5 in addition to the health and welfare impacts of
NOX and PM emissions.
---------------------------------------------------------------------------

\28\ Ground-level ozone, the main ingredient in smog, is formed
by complex chemical reactions of volatile organic compounds (VOC)
and NOX in the presence of heat and sunlight. Standards
that reduce NOX emissions will help address ambient ozone
levels. They can also help reduce particulate matter (PM) levels as
NOX emissions can also be part of the secondary formation
of PM. See Section II.B below.
\29\ According to Airport Council International--North America
and similar FAA databases, most commercial operations occur at
airports that are in or near large cities or urbanized areas. There
are about 130 commercial airports in 78 ozone and fine particulate
nonattainment areas (based on the nonattainment areas status of
2008). There are about 325 commercial airports in the U.S.
\30\ For a current list of nonattainment areas see: http://www.epa.gov/oar/oaqps/greenbk/index.html.
---------------------------------------------------------------------------

A. Inventory Contribution

In contrast to all other mobile sources, whose emissions occur
completely at ground level, the emissions from aircraft and aircraft
engines can be divided into two flight regimes. The first regime
includes the emissions that are released in the lower layer of the
atmosphere and directly affect local and regional ambient air quality.
These emissions generally occur at or below 3,000 feet above ground
level, i.e., during the landing and takeoff (LTO) cycle. The aircraft
operations that comprise an LTO cycle are: engine idle at the terminal
gate (and sometimes during ground delays while holding for the active
runway); taxiing between the terminal and the runway; take-off; climb-
out; and approach to the airport. The second regime includes emissions
that occur above 3,000 feet above ground level, known as non-LTO
emissions. Collectively, the emissions associated with all ground and
flight operations are generally referred to as full flight emissions.
In this section, we will discuss NOX emission
inventories for commercial turbine-engine aircraft, both nationally and
for selected ozone and PM2.5 nonattainment areas (NAAs).
These inventories reflect emissions during the landing and takeoff
cycle only. The most recent comprehensive analysis of historical and
current LTO emissions from aircraft engines comes from a study
undertaken for us by Eastern Research Group (ERG).\31\ The study
analyzed the national emissions of commercial aircraft operations in
the United States, and showed that in the most recent year studied
(2008), such aircraft LTO operations contributed about 97 thousand tons
to the national NOX inventory.\32\ A summary of the national
inventory of LTO NOX emissions is shown in Table 1.
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\31\ ``Historical Assessment of Aircraft Landing and Take-off
Emissions (1986-2008),'' Eastern Research Group, May 2011. A copy of
this document can be found in public docket EPA-HQ-OAR-2010-0687.
\32\ The cumulative LTO NOX reduction associated with
the new NOX standards is projected to be about 100,000
tons from 2014 to 2030 (2014 is the implementation date of the CAEP/
8 NOX standards). See ``Historical Assessment of Aircraft
Landing and Take-off Emissions (1986-2008),'' Eastern Research
Group, May 2011. A copy of this document can be found in public
docket EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

When these nationwide LTO emissions are compared to the total U.S.
mobile source inventory for 2009, they account for less than one
percent of the total. However, such a comparison may be a bit
misleading, as it only includes those aircraft emissions that occur
below 3,000 feet altitude, while comparing them to the entirety of
other mobile source emissions. In the U.S., LTO emissions account for
only about ten percent of full flight NOX emissions. When
considering full flight aircraft emissions (i.e., including both LTO
and non-LTO emissions), the contribution of aircraft to the total
mobile source NOX inventory is approximately 7.7
percent.\33\ It is also worth noting that these LTO emissions are more
localized in that they occur near airports, which are mostly within
urban areas.
---------------------------------------------------------------------------

\33\ U.S. EPA, ``Comparison of Aircraft LTO and Full Flight
NOX Emissions to Total Mobile Source NOX
Emissions,'' memorandum from John Mueller, Assessment and Standards
Division, Office of Transportation and Air Quality, to docket EPA-
HQ-OAR-2010-0687, May 10, 2011.

[[Page 36347]]

Table 1--Current National NOX Emissions From Commercial Aircraft
------------------------------------------------------------------------
2008 Total NOX
Aircraft category (thousand tons)
------------------------------------------------------------------------
Air Carrier.......................................... 86
Commuter/Air Taxi.................................... 11
------------------
Total Commercial................................. 97
------------------------------------------------------------------------

In addition, it is important to assess the contribution of
commercial aircraft LTO NOX emissions on a local level,
especially in areas containing or adjacent to airports. The historical
analysis conducted by ERG also included an assessment of selected ozone
nonattainment areas (NAAs). The NAAs selected for study were chosen as
follows. First, the 25 NAAs with airports which had high commercial
traffic volumes were identified. Second, the 25 NAAs with the largest
population were identified. These lists were combined. However, there
was some overlap, and this led to a total of 40 NAAs being identified
for the study.\34\ These NAAs collectively include 200 airports,
accounting for about 70 percent of commercial air traffic operations.
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\34\ Although 41 NAAs were studied, the non-aircraft emissions
data source that the aircraft emissions were compared to for this
analysis did not distinguish between the Boston NAA in Massachusetts
and the greater Boston NAA in New Hampshire. Thus, aircraft
emissions from those two NAAs were combined into a single NAA for
the purpose of this analysis, yielding 40 NAAs for study.
---------------------------------------------------------------------------

Of the 40 NAAs originally studied by ERG as previously described,
we identified the 30 areas that were in nonattainment for ozone or
PM2.5 as of March 30, 2012.\35\ Current (2008) and projected
(2020) NOX emissions for these 30 ozone and PM2.5
NAAs, as well as the percent contribution of aircraft to total mobile
source inventories (as compared to 2005 and 2020 mobile source
inventories), are shown in Table 2.^{36 37 38} The relative
contribution of aircraft in any given NAA varies based on activity in
other transportation and industrial sectors. As can be seen from this
table, expected growth in aircraft operations in many of these areas
combined with anticipated reductions in NOX emissions from
other mobile source categories results in the growth of the relative
contribution of aircraft LTO emissions to mobile source NOX
emissions in NAAs.
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\35\ For a current list of nonattainment areas see: http://www.epa.gov/oar/oaqps/greenbk/index.html.
\36\ U.S. EPA, ``Relative Contribution of Aircraft to Total
Mobile Source NOX Emissions in Selected Ozone
Nonattainment Areas,'' memorandum from John Mueller, Assessment and
Standards Division, Office of Transportation and Air Quality, to
docket EPA-HQ-OAR-2010-0687, May 10, 2011.
\37\ U.S. EPA, ``Addendum to `Relative Contribution of Aircraft
to Total Mobile Source NOX Emissions in Selected Ozone
Nonattainment Areas,' '' memorandum from John Mueller, Assessment
and Standards Division, Office of Transportation and Air Quality, to
docket EPA-HQ-OAR-2010-0687, May 17, 2011.
\38\ U.S. EPA, ``Update to `Relative Contribution of Aircraft to
Total Mobile Source NOX Emissions in Selected Ozone
Nonattainment Areas,' '' memorandum from John Mueller, Assessment
and Standards Division, Office of Transportation and Air Quality, to
docket EPA-HQ-OAR-2010-0687, April 30, 2012.

Table 2--NOX Emissions in Selected Ozone and PM2.5 Nonattainment Areas
----------------------------------------------------------------------------------------------------------------
2008 Aircraft 2020 Aircraft
Nonattainment area 2008 Total NOX percent of mobile percent of mobile
(tons) source NOX source NOX
----------------------------------------------------------------------------------------------------------------
Atlanta, GA............................................ 5,808 2.6 8.2
Baltimore, MD.......................................... 1,148 1.3 4.4
Boston--including MA and NH NAAs....................... 2,032 1.0 2.7
Charlotte-Gastonia-Rock Hill, NC-SC.................... 1,917 2.6 10.0
Chicago-Gary-Lake County, IL-IN........................ 6,007 1.8 5.0
Cleveland-Akron-Lorain, OH............................. 680 0.5 1.3
Dallas-Fort Worth, TX.................................. 3,880 1.7 6.9
Denver-Boulder-Greeley-Fort Collins-Loveland, CO....... 2,649 2.5 7.1
Detroit-Ann Arbor, MI.................................. 2,312 1.1 3.0
Greater Connecticut, CT................................ 405 0.8 2.4
Houston-Galveston-Brazoria, TX......................... 3,045 1.3 3.4
Indianapolis, IN....................................... 1,089 1.4 3.0
Las Vegas, NV.......................................... 2,308 6.0 15.8
Los Angeles South Coast Air Basin, CA.................. 6,479 1.5 4.5
Louisville, KY-IN...................................... 1,211 1.9 6.2
Milwaukee-Racine, WI................................... 557 0.9 3.2
New York-N. New Jersey-Long Island, NY-NJ-CT........... 10,093 2.3 6.3
Philadelphia-Wilmington-Atlantic City, PA-NY-MD-DE..... 2,308 1.0 2.8
Phoenix-Mesa, AZ....................................... 2,298 1.4 3.3
Pittsburgh-Beaver Valley, PA........................... 480 0.5 1.1
Providence (entire State), RI.......................... 232 1.0 2.3
Riverside County (Coachella Valley), CA................ 70 0.2 0.5
Sacramento Metro, CA................................... 603 1.0 2.0
Salt Lake City, UT..................................... 1,235 4.4 14.1
San Diego, CA.......................................... 1,035 1.4 3.4
San Francisco Bay Area, CA............................. 4,405 2.7 6.7
San Joaquin Valley, CA................................. 74 0.0 0.1
Seattle-Tacoma, WA..................................... 1,958 1.4 3.9
St. Louis, MO-IL....................................... 810 0.6 1.6
Washington, DC-MD-VA................................... 2,983 2.0 6.2
----------------------------------------------------------------------------------------------------------------

Table 3 shows how commercial aircraft operations are projected to
rise in the future on a nationwide basis. As operations increase, the
inventory impact of these aircraft on national and local NOX
inventories will also increase.

[[Page 36348]]

Table 3--Current and Projected Commercial Aircraft Operations
----------------------------------------------------------------------------------------------------------------
Total increase in
Air carrier Commuter/air Total commercial commercial
Year operations taxi operations operations operations over
(millions) (millions) (millions) 2008 (percent)
----------------------------------------------------------------------------------------------------------------
2008................................ 14.1 13.8 27.9
2020................................ 16.5 14.1 30.5 9
2030................................ 20.6 16.0 36.6 31
----------------------------------------------------------------------------------------------------------------
Source: December 2010 FAA TAF, which is located at http://aspm.faa.gov/main/taf.asp.

B. Health, Environmental and Air Quality Impacts

NOX emissions from aircraft and other mobile and
stationary sources contribute to the formation of ozone. In addition,
NOX emissions at low altitude also react in the atmosphere
to form secondary fine particulate matter (PM2.5),
particularly ammonium nitrate. In the following sections we discuss the
adverse health and welfare effects associated with NOX
emissions, in addition to the current and projected levels of ozone and
PM across the country. The ICAO NOX standards with which we
are aligning will help reduce ambient ozone and secondary PM levels and
thus will help areas with airports achieve or maintain attainment with
the National Ambient Air Quality Standards (NAAQS).\39\
---------------------------------------------------------------------------

\39\ The discussion of PM health and welfare effects throughout
this notice relates exclusively to the effects of the NOX
emission standards on the formation of secondary PM from nitrate
formation in the atmosphere. Presently, there are no emission
standards for PM emitted directly from aircraft turbine engines. The
current and planned future work programs for CAEP/ICAO are
developing PM test procedures and information to characterize the
amount and type of these emissions from aircraft engines that are in
production. Ultimately, this information will be used to assess the
need for an aircraft turbine engine PM standard (i.e., whether PM
emissions from aircraft cause or contribute to air pollution which
may reasonably be anticipated to endanger public health or welfare),
with standard setting as appropriate.
---------------------------------------------------------------------------

1. Background on Ozone, PM and NOX
a. What is ozone?
Ground-level ozone pollution is typically formed through reactions
involving VOC and NOX in the lower atmosphere in the
presence of sunlight. These pollutants, often referred to as ozone
precursors, are emitted by many types of pollution sources, such as
highway and nonroad motor vehicles and engines, power plants, chemical
plants, refineries, makers of consumer and commercial products,
industrial facilities, and smaller area sources.
The science of ozone formation, transport, and accumulation is
complex.\40\ Ground-level ozone is produced and destroyed in a cyclical
set of chemical reactions, many of which are sensitive to temperature
and sunlight. When ambient temperatures and sunlight levels remain high
for several days and the air is relatively stagnant, ozone and its
precursors can build up and result in more ozone than typically occurs
on a single high-temperature day. Ozone and its precursors can be
transported hundreds of miles downwind from precursor emissions,
resulting in elevated ozone levels even in areas with low local VOC or
NOX emissions.
---------------------------------------------------------------------------

\40\ U.S. EPA Air Quality Criteria for Ozone and Related
Photochemical Oxidants (Final). U.S. Environmental Protection
Agency, Washington, DC, EPA 600/R-05/004aF-cF, 2006. This document
is available in Docket EPA-HQ-OAR-2010-0687. This document may be
accessed electronically at: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.
---------------------------------------------------------------------------

b. What is particulate matter?
The discussion includes PM2.5 because the NOX
emitted by aircraft engines can react in the atmosphere to form
nitrate, a component of PM2.5. Particulate matter is a
generic term for a broad class of chemically and physically diverse
substances. It can be principally characterized as discrete particles
that exist in the condensed (liquid or solid) phase spanning several
orders of magnitude in size. Since 1987, EPA has delineated that subset
of inhalable particles small enough to penetrate to the thoracic region
(including the tracheobronchial and alveolar regions) of the
respiratory tract (referred to as thoracic particles). The current PM
NAAQS uses PM2.5 as the indicator for fine particles (with
PM2.5 generally referring to particles with a nominal mean
aerodynamic diameter less than or equal to 2.5 micrometers ([micro]m)),
and use PM10 as the indicator for purposes of regulating the
coarse fraction of PM10 (referred to as thoracic coarse
particles or coarse-fraction particles; generally including particles
with a nominal mean aerodynamic diameter greater than 2.5 [micro]m and
less than or equal to 10 [micro]m, or PM10-2.5). Ultrafine
particles are a subset of fine particles, generally less than 100
nanometers (0.1 [mu]m) in diameter.
Fine particles are produced primarily by combustion processes and
by transformations of gaseous emissions (e.g., SOX,
NOX and VOC) in the atmosphere. The chemical and physical
properties of PM2.5 may vary greatly with time, region,
meteorology, and source category. Thus, PM2.5 may include a
complex mixture of different components including sulfates, nitrates,
organic compounds, elemental carbon and metal compounds. These
particles can remain in the atmosphere for days to weeks and travel
hundreds to thousands of kilometers.
c. What is NOX?
Nitrogen dioxide (NO2) is a member of the NOX
family of gases. Most NO2 is formed in the air from the
oxidation of nitric oxide (NO) emitted when fuel is burned at a high
temperature. NO2 and its gas phase oxidation products can
dissolve in water droplets and further oxidize to form nitric acid
which reacts with ammonia to form nitrates, an important component of
ambient PM. NOX and VOC are the two major precursors of
ozone. The health effects of ozone, ambient PM and NOX are
covered in section II.B.2.
2. Health Effects Associated With Exposure to Ozone, PM and
NOX
a. What are the health effects of ozone?
The health and welfare effects of ozone are well documented and are
assessed in EPA's 2006 Air Quality Criteria Document and 2007 Staff
Paper.^{41 42} People who are more susceptible to effects
associated with exposure to ozone can include children,

[[Page 36349]]

the elderly, and individuals with respiratory disease such as asthma.
Those with greater exposures to ozone, for instance due to time spent
outdoors (e.g., children and outdoor workers), are of particular
concern. Ozone can irritate the respiratory system, causing coughing,
throat irritation, and breathing discomfort. Ozone can reduce lung
function and cause pulmonary inflammation in healthy individuals. Ozone
can also aggravate asthma, leading to more asthma attacks that require
medical attention and/or the use of additional medication. Thus,
ambient ozone may cause both healthy and asthmatic individuals to limit
their outdoor activities. In addition, there is suggestive evidence of
a contribution of ozone to cardiovascular-related morbidity and highly
suggestive evidence that short-term ozone exposure directly or
indirectly contributes to non-accidental and cardiopulmonary-related
mortality, but additional research is needed to clarify the underlying
mechanisms causing these effects. In a report on the estimation of
ozone-related premature mortality published by the National Research
Council (NRC), a panel of experts and reviewers concluded that short-
term exposure to ambient ozone is likely to contribute to premature
deaths and that ozone-related mortality should be included in estimates
of the health benefits of reducing ozone exposure.\43\ Animal
toxicological evidence indicates that with repeated exposure, ozone can
inflame and damage the lining of the lungs, which may lead to permanent
changes in lung tissue and irreversible reductions in lung function.
The respiratory effects observed in controlled human exposure studies
and animal studies are coherent with the evidence from epidemiologic
studies supporting a causal relationship between acute ambient ozone
exposures and increased respiratory-related emergency room visits and
hospitalizations in the warm season. In addition, there is suggestive
evidence of a contribution of ozone to cardiovascular-related morbidity
and non-accidental and cardiopulmonary mortality.
---------------------------------------------------------------------------

\41\ U.S. EPA Air Quality Criteria for Ozone and Related
Photochemical Oxidants (Final). U.S. Environmental Protection
Agency, Washington, DC, EPA 600/R-05/004aF-cF, 2006. This document
is available in Docket EPA-HQ-OAR-2010-0687. This document may be
accessed electronically at: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.
\42\ U.S. EPA (2007) Review of the National Ambient Air Quality
Standards for Ozone, Policy Assessment of Scientific and Technical
Information. OAQPS Staff Paper.EPA-452/R-07-003. This document is
available in Docket EPA-HQ-OAR-2010-0687. This document is available
electronically at: http:www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_sp.html.
\43\ National Research Council (NRC), 2008. Estimating Mortality
Risk Reduction and Economic Benefits From Controlling Ozone Air
Pollution. The National Academies Press: Washington, DC A copy of
this document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

b. What are the health effects of PM?
Scientific studies show ambient PM is associated with a series of
adverse health effects. These health effects are discussed in detail in
EPA's Integrated Science Assessment for Particulate Matter (ISA).\44\
The ISA summarizes health effects evidence associated with both short-
term and long-term exposures to PM2.5, PM10-2.5,
and ultrafine particles.
---------------------------------------------------------------------------

\44\ U.S. EPA (2009) Integrated Science Assessment for
Particulate Matter, EPA 600/R-08/139F. A copy of this document is in
docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

The ISA concludes that health effects associated with short-term
exposures (hours to days) to ambient PM2.5 include
mortality, cardiovascular effects, such as altered vasomotor function
and myocardial ischemia, and hospital admissions and emergency
department visits for ischemic heart disease and congestive heart
failure, and respiratory effects, such as exacerbation of asthma
symptoms in children and hospital admissions and emergency department
visits for chronic obstructive pulmonary disease and respiratory
infections.\45\ The ISA notes that long-term exposure (months to years)
to PM2.5 is associated with the development/progression of
cardiovascular disease, premature mortality, and respiratory effects,
including reduced lung function growth in children, increased
respiratory symptoms, and asthma development.\46\ The ISA concludes
that the currently available scientific evidence from epidemiologic,
controlled human exposure, and toxicological studies supports a causal
association between short- and long-term exposures to PM2.5
and cardiovascular effects and premature mortality. Furthermore, the
ISA concludes that the collective evidence supports likely causal
associations between short- and long-term PM2.5 exposures
and respiratory effects. The ISA also concludes that the scientific
evidence is suggestive of a causal association for reproductive and
developmental effects including respiratory-related infant mortality
and cancer, mutagenicity, and genotoxicity and long-term exposure to
PM2.5.\47\
---------------------------------------------------------------------------

\45\ U.S. EPA (2009). Integrated Science Assessment for
Particulate Matter (Final Report). U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-08/139F, 2009. Section 2.3.1.1.
\46\ U.S. EPA (2009). Integrated Science Assessment for
Particulate Matter (Final Report). U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-08/139F, 2009. page 2-12, Sections
7.3.1.1 and 7.3.2.1.
\47\ U.S. EPA (2009). Integrated Science Assessment for
Particulate Matter (Final Report). U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-08/139F, 2009. Section 2.3.2.
---------------------------------------------------------------------------

For PM10-2.5, the ISA concludes that the current
evidence is suggestive of a causal relationship between short-term
exposures and premature mortality, cardiovascular effects, and
respiratory effects. Data are inadequate to draw conclusions regarding
the health effects associated with long-term exposure to
PM10-2.5.
For ultrafine particles, the ISA concludes that there is suggestive
evidence of a causal relationship between short-term exposures and
cardiovascular effects, such as changes in heart rhythm and blood
vessel function. It also concludes that there is suggestive evidence of
association between short-term exposure to ultrafine particles and
respiratory effects. Data are inadequate to draw conclusions regarding
the health effects associated with long-term exposure to ultrafine
particles.
c. What are the health effects of NOX?
Information on the health effects of NO2 can be found in
the EPA Integrated Science Assessment (ISA) for Nitrogen Oxides.\48\
The EPA has concluded that the findings of epidemiologic, controlled
human exposure, and animal toxicological studies provide evidence that
is sufficient to infer a likely causal relationship between respiratory
effects and short-term NO2 exposure. The ISA concludes that
the strongest evidence for such a relationship comes from epidemiologic
studies of respiratory effects including symptoms, emergency department
visits, and hospital admissions. The ISA also draws two broad
conclusions regarding airway responsiveness following NO2
exposure. First, the ISA concludes that NO2 exposure may
enhance the sensitivity to allergen-induced decrements in lung function
and increase the allergen-induced airway inflammatory response
following 30-minute exposures of asthmatics to NO2
concentrations as low as 0.26 ppm. Second, exposure to NO2
has been found to enhance the inherent responsiveness of the airway to
subsequent nonspecific challenges in controlled human exposure studies
of asthmatic subjects. Small but significant increases in non-specific
airway hyperresponsiveness were reported following 1-hour exposures of
asthmatics to 0.1 ppm NO2. Enhanced airway responsiveness
could have important clinical implications for asthmatics since
transient increases in airway responsiveness following NO2
exposure have the potential to increase symptoms and worsen asthma
control. Together, the epidemiologic and experimental data sets form a
plausible, consistent, and coherent description of

[[Page 36350]]

a relationship between NO2 exposures and an array of adverse
health effects that range from the onset of respiratory symptoms to
hospital admission.
---------------------------------------------------------------------------

\48\ U.S. EPA (2008). Integrated Science Assessment for Oxides
of Nitrogen--Health Criteria (Final Report). EPA/600/R-08/071.
Washington, DC: U.S. EPA. A copy of this document is in docket
number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

Although the weight of evidence supporting a causal relationship is
somewhat less certain than that associated with respiratory morbidity,
NO2 has also been linked to other health endpoints. These
include all-cause (non-accidental) mortality, hospital admissions or
emergency department visits for cardiovascular disease, and decrements
in lung function growth associated with chronic exposure.
3. Environmental Effects Associated With Exposure to Ozone, PM and
NOX
a. Deposition of Nitrogen
Emissions of NOX from aircraft engines contribute to
atmospheric deposition of nitrogen in the U.S. Atmospheric deposition
of nitrogen contributes to acidification, altering biogeochemistry and
affecting animal and plant life in terrestrial and aquatic ecosystems
across the United States. The sensitivity of terrestrial and aquatic
ecosystems to acidification from nitrogen deposition is predominantly
governed by geology. Prolonged exposure to excess nitrogen deposition
in sensitive areas acidifies lakes, rivers and soils. Increased acidity
in surface waters creates inhospitable conditions for biota and affects
the abundance and nutritional value of preferred prey species,
threatening biodiversity and ecosystem function. Over time, acidifying
deposition also removes essential nutrients from forest soils,
depleting the capacity of soils to neutralize future acid loadings and
negatively affecting forest sustainability. Major effects include a
decline in sensitive forest tree species, such as red spruce (Picea
rubens) and sugar maple (Acer saccharum); and a loss of biodiversity of
fishes, zooplankton, and macro invertebrates.
In addition to the role nitrogen deposition plays in acidification,
nitrogen deposition also leads to nutrient enrichment and altered
biogeochemical cycling. In aquatic systems increased nitrogen can alter
species assemblages and cause eutrophication. In terrestrial systems
nitrogen loading can lead to loss of nitrogen sensitive lichen species,
decreased biodiversity of grasslands, meadows and other sensitive
habitats, and increased potential for invasive species.
Adverse impacts on soil chemistry and plant life have been observed
for areas heavily influenced by atmospheric deposition of nutrients,
metals and acid species, resulting in species shifts, loss of
biodiversity, forest decline damage to forest productivity and
reductions in ecosystem services. Potential impacts also include
adverse effects to human health through ingestion of contaminated
vegetation or livestock (as in the case for dioxin deposition),
reduction in crop yield, and limited use of land due to contamination.
Atmospheric deposition of pollutants can reduce the aesthetic
appeal of buildings and culturally important articles through soiling,
and can contribute directly (or in conjunction with other pollutants)
to structural damage by means of corrosion or erosion.\49\ Atmospheric
deposition may affect materials principally by promoting and
accelerating the corrosion of metals, by degrading paints, and by
deteriorating building materials such as concrete and limestone.
Particles contribute to these effects because of their electrolytic,
hygroscopic, and acidic properties, and their ability to adsorb
corrosive gases (principally sulfur dioxide).
---------------------------------------------------------------------------

\49\ U.S. EPA. (2005). Review of the National Ambient Air
Quality Standards for Particulate Matter: Policy Assessment of
Scientific and Technical Information, OAQPS Staff Paper. Retrieved
on April 9, 2009 from http://www.epa.gov/ttn/naaqs/standards/pm/data/pmstaffpaper_20051221.pdf.
---------------------------------------------------------------------------

b. Visibility Effects
NOX emissions contribute to visibility impairment in the
U.S. through the formation of secondary PM2.5.\50\
Visibility impairment is caused by light scattering and absorption by
suspended particles and gases. Visibility is important because it has
direct significance to people's enjoyment of daily activities in all
parts of the country. Individuals value good visibility for the well-
being it provides them directly, where they live and work, and in
places where they enjoy recreational opportunities. Visibility is also
highly valued in significant natural areas, such as national parks and
wilderness areas, and special emphasis is given to protecting
visibility in these areas. For more information on visibility see the
final 2009 PM ISA.\51\
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\50\ U.S. EPA. (2004). Air Quality Criteria for Particulate
Matter (AQCD). Volume I Document No. EPA600/P-99/002aF and Volume II
Document No. EPA600/P-99/002bF. Washington, DC: U.S. Environmental
Protection Agency. Retrieved on March 18, 2009 from http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=87903.
\51\ U.S. EPA (2009). Integrated Science Assessment for
Particulate Matter (Final Report). U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-08/139F, 2009. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

c. Plant and Ecosystem Effects of Ozone
Elevated ozone levels contribute to environmental effects, with
impacts to plants and ecosystems being of most concern. Ozone can
produce both acute and chronic injury in sensitive species depending on
the concentration level and the duration of the exposure. Ozone effects
also tend to accumulate over the growing season of the plant, so that
even low concentrations experienced for a longer duration have the
potential to create chronic stress on vegetation. Ozone damage to
plants includes visible injury to leaves and impaired photosynthesis,
both of which can lead to reduced plant growth and reproduction,
resulting in reduced crop yields, forestry production, and use of
sensitive ornamentals in landscaping. In addition, the impairment of
photosynthesis, the process by which the plant makes carbohydrates (its
source of energy and food), can lead to a subsequent reduction in root
growth and carbohydrate storage below ground, resulting in other, more
subtle plant and ecosystems impacts. These latter impacts include
increased susceptibility of plants to insect attack, disease, harsh
weather, interspecies competition and overall decreased plant vigor.
The adverse effects of ozone on forest and other natural vegetation can
potentially lead to species shifts and loss from the affected
ecosystems, resulting in a loss or reduction in associated ecosystem
goods and services. Lastly, visible ozone injury to leaves can result
in a loss of aesthetic value in areas of special scenic significance
like national parks and wilderness areas. The final 2006 Ozone Air
Quality Criteria Document presents more detailed information on ozone
effects on vegetation and ecosystems.
4. Impacts on Ambient Air Quality
The aircraft NOX emission standards we are promulgating
would affect ambient concentrations of air pollutants. Nationally,
levels of PM2.5, ozone, and NOX are
declining.\52\ However as of March 30, 2012, over 15 million people
live in areas designated nonattainment for one or more of the current
NAAQS.\53\ These numbers do not include the people living in areas
where there is a future risk of failing to maintain or attain the
NAAQS.
---------------------------------------------------------------------------

\52\ U. S. EPA (2010) Our Nation's Air: Status and Trends
through 2008. Office of Air Quality Planning and Standards, Research
Triangle Park, NC. Publication No. EPA 454/R-09-002. This document
can be accessed electronically at: http://www.epa.gov/airtrends/2010/.
\53\ U.S. EPA, 2012. http://www.epa.gov/oar/oaqps/greenbk/index.html
---------------------------------------------------------------------------

States with ozone nonattainment areas are required to take action
to bring

[[Page 36351]]

those areas into attainment. The attainment date assigned to an ozone
nonattainment area is based on the area's classification. Most ozone
nonattainment areas are required to attain the 1997 8-hour ozone NAAQS
in the 2007 to 2013 time frame and then to maintain it thereafter.\54\
We anticipate designating areas for the 2008 ozone standards in late
spring 2012; thus, the attainment dates for areas designated
nonattainment for the 2008 8-hour ozone NAAQS would likely be in the
2015 to 2032 timeframe, depending on the severity of the problem in
each area.\55\
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\54\ The Los Angeles South Coast Air Basin 8-hour ozone
nonattainment area and the San Joaquin Valley Air Basin 8-hour ozone
nonattainment area are designated as extreme and will have to attain
before June 15, 2024. The Sacramento, Coachella Valley and Houston
8-hour ozone nonattainment areas are designated as severe and will
have to attain by June 15, 2019. In addition, the Western Mojave 8-
hour ozone nonattainment area has requested to be reclassified as
severe. This request has not yet been acted on.
\55\ U.S. EPA, 2012. Proposed Rule--Implementation of the 2008
National Ambient Air Quality Standards for Ozone: Nonattainment Area
Classifications Approach, Attainment Deadlines and Revocation of the
1997 Ozone Standards for Transportation Conformity Purposes. (77 FR
8107, February 14, 2012).
---------------------------------------------------------------------------

Areas designated as not attaining the 1997 PM2.5 NAAQS
will need to attain the 1997 standards in the 2010 to 2015 time frame,
and then maintain compliance with them thereafter. The 2006 24-hour
PM2.5 nonattainment areas will be required to attain the
2006 24-hour PM2.5 NAAQS in the 2014 to 2019 time frame and
then be required to maintain the 2006 24-hour PM2.5 NAAQS
thereafter.
EPA has already adopted many emission control programs that are
expected to reduce ambient ozone and PM2.5 levels and which
will assist in reducing the number of areas that fail to achieve the
NAAQS. Even so, our air quality modeling projects that in 2030 as many
as 10 counties with a population of over 30 million may not attain the
2008 ozone standard of 0.075 ppm (75 ppb) without additional
controls.\56\ In addition, our air quality modeling projects that in
2030 at least four counties with a population of nearly 7 million may
not attain the 1997 annual PM2.5 standard of 15 [mu]g/m\3\
and 22 counties with a population of over 33 million may not attain the
2006 24-hour PM2.5 standard of 35 [mu]g/m\3\ without
additional controls.^{57 58} These numbers do not account for
those areas that are close to (e.g., within 10 percent of) the
standards. These areas, although not violating the standards, would
also benefit from any reductions in NOX ensuring long-term
maintenance of the NAAQS.
---------------------------------------------------------------------------

\56\ U.S. EPA (2010). Regulatory Impact Analysis: Final
Rulemaking To Establish Greenhouse Gas Emission Standards and Fuel
Efficiency Standards for Medium- and Heavy-Duty Engines and
Vehicles. Chapter 8: Health and Environmental Impacts. EPA 420-R-11-
901.
\57\ U.S. EPA (2010). Regulatory Impact Analysis: Final
Rulemaking To Establish Greenhouse Gas Emission Standards and Fuel
Efficiency Standards for Medium- and Heavy-Duty Engines and
Vehicles. Chapter 8: Health and Environmental Impacts. EPA 420-R-11-
901.
\58\ These figures are based on the results of EPA computer
modeling, which is not affected by the upcoming 2008 ozone NAAQS
nonattainment designations.
---------------------------------------------------------------------------

In summary, the aircraft NOX reductions resulting from
these new aircraft engine emission standards will be useful to states
in attaining or maintaining the ozone, PM2.5, and
NO2 NAAQS standards.

IV. Details of the Final Rule

The following is a description of the regulations being adopted in
this final rule, with any changes from the proposal also noted. The
descriptions also include our response to the most significant comments
received on the proposal. A full summary of the comments and our
responses are contained in the response to comments document for the
rule that is available in the public docket for this action.\59\
---------------------------------------------------------------------------

\59\ U.S. Environmental Protection Agency, ``Summary and
Analysis of Comments: Control of Air Pollution From Aircraft and
Aircraft Engines,'' Office of Transportation and Air Quality, EPA-
420-R-12-011, May 2012. A copy of this document is in docket number
EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

We are establishing two different levels or ``tiers'' of
increasingly more stringent NOX emission standards for gas
turbofan engines with maximum rated thrusts greater than 26.7
kilonewtons (kN).\60\ Each of the tiers apply to newly-certified
engines. Newly-certified aircraft engines are those that would receive
a new type certificate after the effective date of the applicable
standards. Such engine types or models would not have begun production
prior to the effective date of the new requirement.\61\
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\60\ The standards will apply to engines used in commercial and
noncommercial aviation for which the FAA issues airworthiness
certificates, e.g., non-revenue, general aviation service. The vast
majority of these engines are used in commercial applications.
\61\ ICAO standards describe newly-certified engines as ``* * *
engines of a type or model for which the date of manufacture of the
first individual production model was after. * * *'' the effective
date of the emission standards. See ICAO, ``Aircraft Engine
Emissions,'' Annex 16, Volume II, Third Edition, July 2008,
Amendment 4 effective on July 20, 2008. Copies of this document can
be obtained from the ICAO Web site at www.icao.int. The term ``first
individual production model'' means the first engine ever produced
of a unique model or type.
---------------------------------------------------------------------------

We are also requiring newly-manufactured engines to comply with the
first tier of the two tiers of standards. Newly-manufactured aircraft
engines are those that have been previously certified and manufactured
in compliance with preexisting standards, and will continue to be
produced after the effective date of a new applicable standard.
Normally, these newly-manufactured engines must comply with the same
NOX limits as newly-certified engines, but at a later date
or cease production.\62\ The end of this ``phase-in'' period for the
newly-manufactured engine standards is sometimes referred to as a
``production cutoff.''. Again, we are adopting only the first of the
two new tiers of NOX standards for newly-manufactured
engines. These provisions are described in detail below.
---------------------------------------------------------------------------

\62\ The standards for newly-manufactured engines are described
in general regulatory terms as the date that the type or model was
first certified and produced in conformance with specific emission
standards, and the date beyond which an individual engine meeting
those same requirements cannot be made. So ICAO standards describe
newly-manufactured engines as ``* * * engines of a type or model for
which the date of manufacture of the first individual production
model was after. * * *'' the effective date of the applicable
standards, and ``* * * for which the date of manufacture of the
individual engine was on or before. * * *'' a specific date that is
later than the first effective date of the standards. See ICAO,
``Aircraft Engine Emissions,'' Annex 16, Volume II, Third Edition,
July 2008, Amendment 4 effective on July 20, 2008. Copies of this
document can be obtained from the ICAO Web site at www.icao.int.
---------------------------------------------------------------------------

Five other regulatory features are being established in this final
rule. First, we are revising provisions for certain time-limited
flexibilities, i.e., potential exemptions, for newly-manufactured
engines that may not be able to comply with the first tier of the new
NOX standards because of specific technical or economic
reasons.\63\ Second, we are defining ``derivative engine'' for
emissions certification purposes. The intent of this definition is to
distinguish when the emission characteristics of a new turbofan engine
model vary substantially from its existing parent engine design, and
must show compliance with the emission standards for a newly-
certificated engine. Third, we are establishing new CO and
NOX standards for turbofan engines that are used to propel
supersonic aircraft. These standards were adopted by ICAO in the 1980s,
but were not previously added to our HC emission standard for these
engines. Promulgating these standards meets our treaty obligation under
the Convention on International Civil Aviation as previously described

[[Page 36352]]

in section I.C. Fourth, we are making several changes to the emission
testing and measurement procedures in our regulations that are intended
to implement ICAO's Annex 16 and to incorporate the entire annex in our
regulations by reference. Finally, as described in section IV, we are
amending the current regulatory provisions that address definitions,
acronyms and abbreviations, general applicability and requirements,
exemptions, and incorporation by reference. These amendments are
intended to clarify requirements, make them more consistent with other
parts of the program, update the text to be consistent with current
standard language conventions, or remove obsolete provisions.
---------------------------------------------------------------------------

\63\ These apply only to the first tier of NOX
standards. We are not adopting a production cutoff for the second
tier of standards.
---------------------------------------------------------------------------

As discussed further below, with the exception of the annual
reporting requirement described in section III.D, the amendments
reflect those changes that were previously adopted by ICAO.
This final rule also is consistent with our authority and
obligations under the CAA as described in section I.B. More
specifically, the technical feasibility and cost of the emission
standards were well documented by our own analyses and CAEP as
described later in this section and in section V, Technical
Feasibility, Costs, and Emission Benefits. We think that the final rule
provides adequate lead time for the development and application of the
requisite technology with appropriate consideration to the cost of
compliance. We have consulted with the Department of Transportation
through the FAA regarding lead time, noise, safety, and the technical
feasibility of the new standards. Today's final rule is also consistent
with U.S. treaty obligations under the Chicago Convention as described
in section I.C., because the requirements are consistent with current
ICAO standards.
Except to the extent needed to make our standards conform to ICAO's
standards by making them applicable to both commercial and non-
commercial engines, we are not revising exhaust emission standards for
HC, CO, or smoke. All engines subject to the new NOX
standards would also continue to be subject to the existing HC, CO, and
smoke standards. It is worth emphasizing that although we are including
these existing HC, CO, and smoke standards in a new section 87.23,
which would also contain the new Tier 6 and Tier 8 NOX
standards, we are not actually adopting new standards for these three
pollutants, since under the current form of part 87 these HC, CO and
smoke standards would already continue to apply to new engine types
subject to future revised NOX standards.
As discussed above, we are adopting a new naming convention in this
preamble and the regulatory text to more easily distinguish between the
tiers of increasingly more stringent NOX emission standards.
This convention is also consistent with the numeric identifier that
CAEP uses to differentiate the CAEP work cycle that produces new
NOX standards. (The CAEP naming convention is described in
section I.E.) As a result, the first tier of NOX standards,
which correspond to CAEP/6, are referred to as Tier 6 in the remainder
of today's notice. The second tier of standards is referred to as Tier
8, which correspond to CAEP/8. We are also incorporating the new naming
convention in the regulations for the existing NOX emission
standards, i.e., Tier 0, Tier 2, and Tier 4. There is no material
change to the existing NOX standards themselves, except to
the extent that when today's final rule becomes effective, the existing
NOX standards would be superseded by Tier 6 standards.
We acknowledge that this new naming convention is a change from the
past practice of not describing aircraft engine emission standards as
tiers. However, we believe the new naming scheme is a valuable tool
that makes referring to individual NOX standards much
easier. It is also similar to the terminology we use for other mobile
source sectors that are subject to environmental regulation and for
which standards have become more stringent or have otherwise been
amended over time.

A. NOX Standards for Newly-Certified Engines

We are adopting two different tiers of increasingly stringent
NOX standards. These standards would apply for all for
newly-certified turbofan aircraft engines with maximum rated thrusts
greater than 26.7 kN.\64\ (See section III.B for a discussion of how
these standards apply for newly-manufactured engines that are not
considered to be newly certified.) The numerical value of the
applicable standard for an individual engine model is defined by the
engine's thrust level and pressure ratio. Simply stated, the pressure
ratio is the numerical ratio of the air pressure entering the engine to
the air pressure at the entrance to the combustor, i.e., after the air
has passed through the compressor section of the engine.\65\ The new
tiers are described separately below.
---------------------------------------------------------------------------

\64\ There are no gaseous emission standards, e.g.,
NOX, for gas turbine engines with maximum rated thrusts
equal to or less than 26.7 kN. These engines are, however, subject
to smoke and fuel venting standards.
\65\ The combustor is a chamber where a mixture of fuel and air
is burned to form very hot, expanding gases. As these gases move
through the combustion chamber, the walls of the combustor are
cooled with dilution air to prevent thermal damage. Dilution air is
also used to tailor the gas' temperature profile as it exits the
combustor so that the final temperatures will not exceed the
allowable limit at the turbine inlet.
---------------------------------------------------------------------------

1. Tier 6 NOX Standards for Newly-Certified Engines
This first tier of new standards is equivalent to the CAEP/6
NOX limits that were adopted by ICAO and became
internationally applicable after December 31, 2007. Given that aircraft
turbofan engines are international commodities, engine manufacturers
introduced engine models after that date that demonstrate compliance
with these international standards, or are already planning to do so
for upcoming engine designs. Based on this, our evaluation of the
necessary lead time, and the lack of any comments on this aspect of the
proposal, this tier of standards takes effect immediately upon the
effective date of this final rule.
The basic form of the NOX standards for turbofan engines
is different for higher- and lower-rated thrust engines. Higher output
engines are defined as having rated thrusts equal to or greater than 89
kN, while lower output engines are defined as having rated thrusts less
than 89 kN but greater than 26.7 kN. The new Tier 6 NOX
standards for each of these power groupings are described separately
below.
a. Numerical Emission Limits for Higher Thrust Engines
The Tier 6 NOX standards for newly-certified gas turbine
engines with rated thrusts more than 89 kN are differentiated by
pressure ratio as shown below.
For engines with a pressure ratio of 30 or less:

g/kN rated output = 16.72 + (1.4080 * engine pressure ratio)
For engines with a pressure ratio of more than 30 but less
than 82.6:

g/kN rated output = -1.04 + (2.0 * engine pressure ratio)
For engines with a pressure ratio of 82.6 or more:

g/kN rated output = 32 + (1.6 * engine pressure ratio)

The new Tier 6 NOX standards for these higher thrust
engines are presented in Figure 1 along with the previous EPA
NOX standards, which were based on CAEP/4, for comparison.

[[Page 36353]]

[GRAPHIC] [TIFF OMITTED] TR18JN12.000

As a matter of convention, the relative stringency from one CAEP
standard to another is expressed relative to a pressure ratio of 30,
because the percentage reduction is usually inconsistent across all of
the possible pressure ratios, which otherwise makes a simple comparison
difficult. Using that convention, the Tier 6 standards (CAEP/6) are
referred to as being 12 percent more stringent than the existing EPA
NOX Tier 4 standards (CAEP/4). The relative stringency can
also be illustrated at other pressure ratios. At pressure ratios less
than 30 the reductions are also 12 percent. At pressure ratios above
30, however, the percent reduction decreases as the pressure ratio is
increased. Based on the figure, the percent reduction for current
technology engines ranges from about 8 to 12 percent.
b. Numerical Emission Limits for Lower Thrust Engines
The new Tier 6 NOX standards for newly-certified gas
turbine engines with rated thrusts between 26.7 and equal to or less
than 89.0 kN are differentiated by both pressure ratio and rated thrust
as shown below.
For engines with a pressure ratio of 30 or less:

g/kN rated output = 38.5486 + (1.6823 * engine pressure ratio) -
(0.2453 * kN rated thrust) - (0.00308 * engine pressure ratio * kN
rated thrust)

For engines with a pressure ratio of more than 30 but less
than 82.6:

g/kN rated output = 46.1600 + (1.4286 * engine pressure ratio) -
(0.5303 * kN rated thrust) + (0.00642 * engine pressure ratio * kN
rated thrust)

In developing the corresponding NOX standards for lower
thrust engines, CAEP recognized the technical challenges that
physically smaller-sized engines sometimes present relative to
incorporating some of the lowest NOX technology approaches,
which are otherwise available to their larger counterparts. These
technical difficulties are well documented and increase progressively
as size is reduced (from around 89 kN).\66\ For example, the relatively
small combustor space and section height of these engines creates
constraints on the use of low NOX fuel-staged combustor
concepts which inherently require the availability of greater flow path
cross-sectional area than conventional combustors. Also, fuel-staged
combustors need more fuel injectors, and this need is not compatible
with the relatively smaller total fuel flows of lower thrust engines.
(Reductions in fuel flow per nozzle are difficult to attain without
having clogging problems due to the small sizes of the fuel metering
ports.) In addition, lower thrust engine combustors have an inherently
greater liner surface-to-combustion volume ratio, and this requires
increased wall cooling air flow. Thus, less air will be available to
obtain acceptable turbine inlet temperature distribution and for
emissions control.\67\ With these technological constraints in mind,
CAEP fashioned the CAEP/6 NOX standards across the range of
thrusts represented by low-thrust engines to become comparatively less
stringent, i.e., CAEP/6 relative to CAEP/4, as the rated output and
physical size of the engines decrease. We agree with this approach.
---------------------------------------------------------------------------

\66\ ICAO/CAEP, ``Report of Third Meeting, Montreal, Quebec,
December 5-15, 1995,'' Document 9675, CAEP/3. A copy of this paper
can be found in Docket EPA-HQ-OAR-2010-0687.
\67\ ICAO, ``Combined Report of the Certification and Technology
Subgroups,'' section 2.3.6.1, CAEP Working Group 3 (Emissions).
Presented by the Chairman of the Technology Subgroup, Third Meeting,
Bonn, Germany, June 1995. A copy of this paper can be found in
Docket EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

As mentioned, the new Tier 6 standards depend on an individual
engine's rated thrust and pressure ratio. With two variables in the
calculation, the standards cannot be represented in a simple figure,
i.e., no single line graph showing the standards for all engines within
the thrust range is possible as it was for higher thrust engines.
Regardless of this complexity, however, some general observations are
useful to characterize the Tier 6 NOX standards for lower
thrust engines based on the engine size versus technological challenge
described in the previous paragraph.
Comparing the new lower and higher thrust standards at 89 kN, which
is the demarcation point between the two sets of standards, shows that
the standards for lower thrust engines are numerically equivalent to
the limit for higher thrust

[[Page 36354]]

engines at each pressure ratio. This is as expected because the engine
sizes and ability to incorporate low-NOX technologies are
the same at 89.0 kN delineation point.
Again focusing only on 89 kN engines, the new Tier 6 standards
represent a 12 percent reduction from the existing EPA Tier 4 (CAEP/4
based standards) for pressure ratios of 30 or less as shown below in
Figure 2. This includes the region represented by almost all current
engine designs. At higher pressure ratios, the relative numerical
reduction is progressively less because the slope of the two standards
is essentially the same.
[GRAPHIC] [TIFF OMITTED] TR18JN12.001

At other thrust ratings the percent reduction between the new Tier
6 and existing EPA NOX standards at any pressure ratio
becomes progressively smaller as thrust decreases. This is illustrated
in Figure 3 for a pressure ratio of 30. This pressure ratio was chosen
for the example because, as before, the relative stringency of CAEP
NOX standards is generally compared at this point as a
matter of convention. As shown in the figure for current engines, the
reduction ranges from 12 percent at the upper end of the thrust range
to 0 percent at the lower end of the range. The pattern is similar for
the other pressure ratios. Only the actual numerical value for
percentage reduction at 89 kN, as shown on the far right of the figure,
may vary by pressure ratio, as described at the beginning of this
paragraph. However, in the region of pressure ratios represented by
today's engines, the results are identical to those shown in the
figure, i.e., a 12 percent reduction at 89 kN decreasing to 0 percent
at 26.7 kN.

[[Page 36355]]

[GRAPHIC] [TIFF OMITTED] TR18JN12.002

2. Tier 8 NOX Standards for Newly-Certified Engines
The second tier of new standards, i.e., Tier 8, are equivalent to
the NOX limits that were most recently recommended at CAEP/8
in February 2010 for adoption by ICAO.\68\ The CAEP/8 recommended
standards have a recommended applicable date after December 31, 2013.
As discussed further in section V of today's notice, we agree with CAEP
that this provides engine manufacturers with adequate lead time to
respond to these more stringent NOX standards considering
the technical feasibility and cost associated with the
requirements.\69\ Therefore, this tier of standards takes effect on
January 1, 2014. As with the new Tier 6 NOX standards, the
basic form of the new Tier 8 standards for turbofan engines is
different for higher- and lower-rated thrust engines. Higher output
engines are defined as having rated thrusts equal to or greater than 89
kN, while lower output engines are defined as having rated thrusts less
than 89 kN but greater than 26.7 kN. The longer-term standards for each
of these power grouping are described separately below.
---------------------------------------------------------------------------

\68\ CAEP/7 did not adopt new aircraft engine NOX
standards.
\69\ Leadtime in this context refers to the time between CAEP
adoption of a new emission standard and the effective date of the
requirement. ICAO emission standards are global in nature and
designed to provide engine manufacturers with adequate time to
develop and deploy the requisite technology. Manufacturers produce
engines that comply with new ICAO standards to ensure their products
can be sold and used worldwide even in the absence of specific U.S.
regulations. Based on this response to the ICAO standard, we find
that there is also adequate leadtime between EPA's promulgation of
the new requirement and the associated effective date. No public
comments pertaining to leadtime were received.
---------------------------------------------------------------------------

a. Numerical Emission Limits for Higher Thrust Engines
The new Tier 8 NOX standards for newly-certified
turbofan engines with rated thrusts of 89 N or more are differentiated
by pressure ratio as shown below.
For engines with a pressure ratio of 30 or less:

g/kN rated output = 7.88 + (1.4080 * engine pressure ratio)

For engines with a pressure ratio of more than 30 but less
than 104.7:

g/kN rated output = -9.88 + (2.0 * engine pressure ratio)

For engines with a pressure ratio of 104.7 or more:

g/kN rated output = 32 + (1.6 * engine pressure ratio)

The new Tier 8 NOX standards for these higher thrust
engines are presented in Figure 4 along with the new Tier 6 standards
for comparison.

[[Page 36356]]

[GRAPHIC] [TIFF OMITTED] TR18JN12.003

As noted previously, as a matter of convention the relative
stringency from one CAEP standard to another is generally expressed
relative to a pressure ratio of 30. Using that convention, the new Tier
8 standards (CAEP/8) are referred to as being 15 percent more stringent
than the new Tier 6 NOX standards (CAEP/6). The relative
stringency can also be illustrated at other pressure ratios. At
pressure ratios less than 30 the reductions increase. At pressure
ratios above 30, however, the percent reduction decreases. Based on the
figure, the percent reduction for current engine designs range from
about 11 to 19 percent.
b. Numerical Emission Limits for Lower Thrust Engines
The new Tier 8 NOX standards for newly-certified gas
turbine engines with rated thrusts between 26.7 but less than or equal
to 89.0 kN are differentiated by both pressure ratio and rated thrust
as shown below.
For engines with a pressure ratio of 30 or less:

g/kN rated output = 40.052 + (1.5681 * engine pressure ratio) - (0.3615
* kN rated thrust) - (0.0018 * engine pressure ratio * kN rated thrust)

For engines with a pressure ratio of more than 30 but less
than 104.7:

g/kN rated output = 41.9435 + (1.505 * engine pressure ratio) -
(0.55823 * kN rated thrust) + (0.005562 * engine pressure ratio * kN
rated thrust)

In developing the corresponding CAEP/8 NOX standards for
low thrust engines, CAEP recognized the technical challenges that
physically smaller-sized engines represent relative to incorporating
some of the lowest NOX technology, which is otherwise
available to their larger counterparts. These technical difficulties
were described in the previous section for the Tier 6 low-thrust engine
standards.
Also as previously described, no single line graph showing the
standards for all engines within the thrust range is possible as it was
for higher thrust engines, because the equations have two variables.
However, some general observations are useful to characterize the new
Tier 8 NOX standards for lower thrust engines based on the
engine size versus technological challenge described in the previous
paragraph. First, the new Tier 8 NOX standards for lower
thrust engines are numerically equivalent to the limit for higher
thrust engines across all pressure ratios at the highest rating of 89
kN, where the engine sizes and ability to incorporated low-
NOX technologies are comparable. This same characteristic
was observed for the Tier 6 standards. Second, as shown below in Figure
5 for 89 kN engines, at this thrust rating the new Tier 8 standards
represents a 15 percent reduction from the Tier 6 standards for a
pressure ratio of 30. However, within the region of pressure ratios for
all current engine designs, the reductions range from 19 to 23 percent.

[[Page 36357]]

[GRAPHIC] [TIFF OMITTED] TR18JN12.004

Third, at other thrust ratings the percent reduction between the
new Tier 6 and Tier 8 standards at any pressure ratio becomes
progressively smaller as thrust decreases. This is illustrated in
Figure 6 for a pressure ratio of 30, following the convention described
above. Also as shown in the figure for current engines, the reduction
ranges from 15 percent at the upper end of the thrust range to 5
percent at the lower end of the range. While not depicted in a figure,
the pattern is similar for the other pressure ratios. However, the
actual numerical values for percentage reductions at both ends of the
thrust range, i.e., 26.7 to 89 kN, may vary by pressure ratio. In the
region of pressure ratios represented by today's engines, the results
are identical to those shown in Figure 6 at 26.7 kN, i.e., a 5 percent
reduction at all pressure ratios for that thrust rating. However,
percent reductions increase linearly up to a maximum 23 percent
reduction for 89 kN engines with pressure ratios of about 15.
[GRAPHIC] [TIFF OMITTED] TR18JN12.005

[[Page 36358]]

B. Application of the Tier 6 NOX Standards to Newly-
Manufactured Engines

This section describes the application of the new Tier 6
NOX standards to newly-manufactured engines, and our amended
temporary flexibilities for newly-manufactured engines that show
significant problems complying with these requirements. Also,
consistent with CAEP/8, we are not applying the new Tier 8
NOX standards to newly-manufactured engines at this time.
This section concludes with a description of future efforts to examine
such a possibility.
1. Phase-In of the Tier 6 NOX Standards for Newly-
Manufactured Engines
As described above, the new Tier 6 NOX standards apply
to all engine types or models that receive a new type certificate after
the effective date of the final rule. We are also phasing in these same
NOX limits for newly-manufactured engines for engine models
(and their derivatives for emissions certification purposes) that were
originally certified to less stringent requirements (i.e., Tier 2 or
Tier 4) and were already being produced for installation on new
aircraft prior to the effective date of the final rule.\70\ As a
result, manufacturers need to bring newly-manufactured engines of these
previously certified models into compliance with the applicable Tier 6
standards by a future date or cease production of those engine
models.\71\ As we discussed and described in our analysis of the need
for a CAEP/6 production cutoff during the CAEP process, establishing a
date certain for compliance with any emission standard is necessary to
ensure that the full benefits of newer, more stringent requirements
will be achieved in a reasonable time.\72\ We are, however, adopting
certain limited flexibilities for engines that cannot be made compliant
because of specific technical or economic reasons, as discussed later
in this section.
---------------------------------------------------------------------------

\70\ The requirement that newly-manufactured engines must meet
the CAEP 6 NOX standard by a date certain applies only to
engines that are intended to be installed on all new airframes. It
would not apply to engines produced as ``spares,'' which are
intended to be installed on existing airframes as replacements for
maintenance or other reasons. See section III.B.2 for more
information about new and spare engines.
\71\ After this date the production of any noncompliant engines
would cease because the FAA would discontinue issuing an
airworthiness approval tag (FAA Form 8130-3) to these engines.
\72\ ICAO, Committee on Aviation Environmental Protection
(CAEP), Eight Meeting, Montreal, 1 to 12 February 2010, Agenda 2:
Review of Technical Proposals Relating to Aircraft Engine Emissions,
Adoption of Production Cutoff for Emission Standards, WP/56,
Presented by the United States, December 12, 2009. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

As described in the proposal, the effective date of January 1, 2013
\73\ for the newly-manufactured engine standards is consistent with the
expected market demand for these previously certified engine types.
Historically, engine manufacturers have often responded to the adoption
of more stringent NOX standards by bringing older engine
types into compliance with the newer requirements well before the
required date in anticipation of the likely market demand, or planning
for the orderly withdrawal of these engines from the marketplace.
Information developed during the ICAO process in 2008 and 2009
^{74 75 76} and our more recent discussions with manufacturers
indicate that: (1) All but a few models are already compliant with
CAEP/6 standards, (2) nearly without exception, all current production
models will meet the CAEP/6 requirements by the 2012 time frame, and
(3) any noncompliant models will be phased out of production because of
low market demand.
---------------------------------------------------------------------------

\73\ The regulatory text specifies that engine models certified
at or below the Tier 4 NOX standards may be produced
through December 31, 2012 without meeting the Tier 6 NOX
standards. Therefore, the effective date of the standards for newly-
manufactured engines is effectively January 1, 2013.
\74\ ICAO, Committee on Aviation Environmental Protection
(CAEP), Steering Group Meeting, Salvador, Brazil, 22 to 26 June
2009, Agenda 6: Emissions Technical-WG3, Production Cutoffs and
Associated Flexibilities for ICAO Engine Emission Standards, WP/39,
Presented by U.S. Representative, August 6, 2009. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.
\75\ ICAO, Committee on Aviation Environmental Protection
(CAEP), Steering Group Meeting, Salvador, Brazil, 22 to 26 June
2009, Agenda Item 3: Forecasting and Economic Analysis Support Group
(FESG), CAEP/6 NOX Production Cutoff Cost Analysis, WP/
39, Presented by the FESG NOX Stringency Task Group,
February 6, 2009. A copy of this document is in docket number EPA-
HQ-OAR-2010-0687.
\76\ ICAO, Committee on Aviation Environmental Protection
(CAEP), Steering Group Meeting, Seattle, 22 to 26 September 2008,
Agenda Item 3: Forecasting and Economic Analysis Support Group
(FESG), Production Cutoff for NOX Standards, WP/6,
Presented by the FESG Rapporteurs, April 9, 2008. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

We think that the five-year phase-in period from ICAO's effective
date of the CAEP/6 standards (corresponding to our new Tier 6
NOX standards) for newly-manufactured engines is adequate
for manufacturers and their customers to respond to the new
requirements without disrupting their future planning and purchasing
decisions.^{77 78} This phase-in period for applying the Tier 6
NOX standards to newly-manufactured engines is also
identical to the date for this same requirement that was adopted by
ICAO. No comments were received expressing concern with this phase-in
period for newly-manufactured engines.
---------------------------------------------------------------------------

\77\ The ICAO CAEP/6 NOX standards became effective
after December 31, 2007.
\78\ This period of time is also consistent with the phase-in
period associated with previous ICAO standards. CAEP's predecessor,
the Committee on Aircraft Engines Emissions, established the first
international emission standards with an effective date four years
after adoption, i.e., effectively a four year phase-in. CAEP2
included a phase-in period of 4 years for newly-manufactured
engines.
---------------------------------------------------------------------------

We did, however, receive two comments expressing the view that the
time between the date of our final rule and the January 1, 2013
effective date of the production cutoff would be too short if it is
less than one year. General Electric Aviation (GE) was the most
detailed and began by noting that most of the engine models currently
in production were certified to the Tier 4 standards and had
demonstrated NOX emissions below the Tier 6 at that time.
They continued that if the original certification reports are
sufficient for the FAA to formally certify these engines to the Tier 6
standards, then none of these engines would be adversely affected by
the production cutoff. However, GE expressed the concern that if
additional interactions or formal action by the FAA were needed, or
revisions to the FAA's FAR Part 34 were required, then having less than
one year between EPA's final rule and the production cutoff could
disrupt current engine production. As a result, GE asked that the date
of the production cutoff be delayed to take effect 12 months after the
final rule, i.e., 2013. The other joint comment from the Aerospace
Industries Association (AIA) and the General Aviation Manufacturers
Association (GAMA) was similar in nature, but without supporting
details.
The commenters' concerns do not relate to the technical or economic
feasibility of newly-manufactured engines achieving emission levels in
compliance with the new Tier 6 standards by the date of the production
cutoff as proposed. The concerns expressed do not argue that additional
time is necessary ``to permit the development and application of the
requisite technology'' to comply with the standards under CAA section
231(b). Therefore, the date of the Tier 6 production cutoff is
appropriate and consistent with the Clean Air Act.
Section 232(b) of the Act directly addresses our obligation
relative to the effective date of the regulation. Specifically, it
says: ``Any regulation prescribed under this section (and any revision
thereof) shall take effect after such period as the Administrator finds
necessary (after consultation with the

[[Page 36359]]

Secretary of Transportation) to permit the development and application
of the requisite technology, giving appropriate consideration to the
cost of compliance within such period.'' Based on the information
provided above, the aircraft engine models described by GE are already
capable of complying with the EPA Tier 6 NOX standards using
already applied requisite technology, i.e., the cost of applying with
has already been borne, as the effective date of the corresponding ICAO
CAEP/6 NOX standard has already passed. We do not believe
there are any technical feasibility or economic implications arising
from the continued application of the requisite technology for those
engines to meet the Tier 6 NOX standards. Also, consistent
with our most recent previous amendment to the NOX
standards, which similarly promulgated the standard at a level that was
already being met by aircraft engine manufacturers who were already
applying the requisite technology, the effective date does not need to
include additional lead time for the development and application of
additional technology that would be needed to comply with the
standards. See, e.g., 70 FR 69604, 69674-76 (Nov. 17, 2005). As a
result, the implementation dates provide more than adequate lead time
under the statute. Therefore, because aircraft engine manufacturers are
already able to comply with the Tier 6 NOX standard through
the continued use of already applied requisite technology, and because
the effective date of the corresponding ICAO CAEP/6 NOX
standard has already passed (and also based on the assessment described
in section V. Technical Feasibility, Cost, and Emission Benefits), we
find that the dates provide more than adequate lead time under the
statute for application of requisite technology.
We also want to stress that the production cutoff is actually an
ICAO standard and we think it is important to stay aligned with the
CAEP production cutoff date. We note that this is also being adopted by
the European Aviation Safety Agency (EASA) and perhaps other aviation
certification authorities. Our adoption of the proposed date insures
international consistency regarding the production cutoff date and
avoids contradicting our international bilateral agreements with other
governments, e.g., the European Union.
Regarding the need for engine models to be formally recognized by
the FAA as complying with the new Tier 6 standard, this is completely
within the purview of the FAA. In our previous most recent amendment to
the NOX standard, we provided just a one-month lead time
period before the revised standard became effective, and FAA did not
adopt corresponding implementing regulations until one year later, with
no apparent disruption to the industry. (See 70 FR 69664, Nov. 17,
2005.) The new Tier 6 standards are the same as the CAEP/6 standards
that were approved by ICAO in 2005 with an effective date of beginning
after December 31, 2007. Therefore, just as for the 2005 revised
NOX standard that we similarly promulgated significantly
later than the effective date of the corresponding ICAO CAEP standard,
we do not believe that it is necessary to delay the effective date
based on a need for the FAA to revise its own implementation and
enforcement regulations.
Finally, section 232(a) of the Act directs the FAA to ensure
compliance with our standards. In this regard, the FAA has developed a
streamlined process to recognize compliance with Tier 6 and or Tier 8
as appropriate for currently type certified engine models which meet
the emission standards and they have assured the regulated industry
that they will dedicate the necessary resources to formally recognize
conformance with the standards before the production cutoff date.
For the reasons stated above, EPA is promulgating the Tier 6
production cutoff with the originally proposed effective date of
January 1, 2013.
2. Carryover of Previously Generated Emission Test Data
Aircraft engine models normally receive type certificates, which
include a determination that the model meets the emission standards in
force at the time the type certificate is granted. EPA has not updated
its aircraft emission standards or test procedure regulations since
2005. In this action we are adopting Tier 6 and Tier 8 NOX
emission standards and are adopting either in 40 CFR part 87 directly
or through incorporation by reference of Annex 16, Volume II a number
of minor changes to test procedures and related requirements. These
changes will become effective on the date when the rule becomes
effective.
This leaves open a question regarding the future validity and
acceptability for amended type certificates of emission tests and
emission test data generated under previously specified test procedures
and related requirements. For example, there may be an engine model
tested in 2004 that demonstrated HC, CO, and NOX emission
levels below the exhaust emission standards in effect at that time and
also below the Tier 6 or perhaps even the Tier 8 standards that are
being promulgated in this final rule. We want to be clear that we do
not intend minor changes to test procedures or related provisions and
requirements to trigger the need for additional testing. Thus, in cases
where a manufacturer has a valid current type certificate based on
emissions information generated under the test procedures in force at
the time the type certificate was granted, we consider that data to be
valid for any formal FAA recognition of compliance, e.g., an amended
type certificate, with the Tier 6 or Tier 8 NOX emission
requirements if the original test data demonstrate such compliance. The
same is true for the HC and CO emission standards. This clarification
should greatly facilitate compliance determinations by the FAA and
eliminate any uncertainty regarding the potential for otherwise minor
test procedure changes to trigger new emissions testing for previously
certificated engines with emission levels below the new NOX
standards.
3. Exemptions and Exceptions From the Tier 6 Production Cutoff
In conjunction with the implementation of the new Tier 6
NOX standards, we are establishing provisions which allow
engine manufacturers to request an exemption or exception from meeting
the Tier 6 NOX standards for newly-manufactured engines.
These provisions replace existing provisions addressing exemptions that
were promulgated in section 87.7 of our aircraft engine regulations.
(Any exemptions previously issued under section 87.7 would not be
affected by the revisions.) This section of the preamble describes
these exemption and exception provisions, i.e., exemptions for engines
installed in new aircraft and exceptions for spare engines used in
existing aircraft for maintenance purposes. It also includes a
description of a short-term exception program (termed the low-volume,
time-limited transitional exemption program). These provisions have
largely been crafted to be consistent with exemption provisions in the
ICAO Environmental Technical Manual (ETM).^{79 80} The
provisions of

[[Page 36360]]

the ETM guidance were developed in the context of the CAEP/6
NOX production cutoff deliberations leading up to the CAEP/8
meeting in February 2010.
---------------------------------------------------------------------------

\79\ ICAO, ``Committee on Aviation Environmental Protection
(CAEP), Report of the Eighth Meeting, Montreal, February 1-12,
2010,'' CAEP/8-WP/80. A copy of this document is in docket number
EPA-HQ-OAR-2010-0687.
\80\ Note that EPA has submitted a paper to amend the exemption
provisions included in this ETM to be consistent with this rule. See
ICAO, ``Newly Produced Engine Exemptions for CAEP/6 NOX
Production Cutoff,'' CAEP9--WG3-CTG-2--IP01, September 23, 2010. A
copy of this document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

While we are revising our regulations, the process for evaluating
any request for an exemption, i.e., petition, and any final decision on
its disposition would be unchanged. In this regard, the FAA is the
process owner under its enforcement authority contained in section 232
of the Clean Air Act.\81\ The FAA must consult with EPA in evaluating
the merits of the request, and the EPA must formally concur with any
decision regarding the granting or denial of the request.
---------------------------------------------------------------------------

\81\ EPA formally transferred the responsibility and authority
for the evaluation of requests for exemptions from the emission
standards to the Secretary of Transportation (DOT). See ``Control of
Air Pollution from Aircraft and Aircraft Engines; Emission Standards
and Test Procedures;'' Final Rule, 47 FR 58462, December 30, 1982.
---------------------------------------------------------------------------

We are deleting from our regulations the requirement in Sec.
87.7(e) that the FAA publish a notice of the exemption in the Federal
Register. The FAA has an established process in place for publishing
requests for exemption that are filed in accordance with 14 CFR part
11. Under Sec. 87.7(b) of the existing regulations, the FAA, with EPA
concurrence, may also exempt low-production volume engines from being
fully compliant with the emission standards. Several such short-term
exemptions were granted in the 1980s when emission standards were first
applied. These exemptions have since expired, and requests for new
exemptions under those provisions have not been submitted. We have
determined that these provisions, which were adopted in conjunction
with revised emission standards in 1982, are no longer of any
utility.\82\ Therefore, we are deleting these provisions to avoid
confusion.
---------------------------------------------------------------------------

\82\ U.S.EPA, ``Control of Air Pollution from Aircraft and
Aircraft Engines; Emission Standards and Test Procedures,'' Final
Rule, 47 FR 58462, December 30, 1982.
---------------------------------------------------------------------------

We are also deleting the time-limited exemption provision for in-
use engines that is contained in section 87.7(d) of the existing
regulations. This provision applies to fuel venting and smoke emission
standards, which were new when the exemption was adopted in 1973. The
exemption allowance was limited to in-use engines that were unable to
comply with the requirements when the regulation became effective in
1974. The in-use fleet of engines was fully retrofitted to comply with
the standards later in the 1970s. Therefore, this provision is now
obsolete and we are deleting it to avoid confusion. We proposed to
delete the existing provisions for temporary exemptions based on
flights for short durations and infrequent intervals. This proposal was
based on the EPA's and FAA's belief that the provisions were
unnecessary because our standards apply to aircraft certificated by the
FAA, and the FAA does not address in the certification process whether
an aircraft will be used for short durations or infrequent intervals.
Hence, the provisions appeared to have no utility.
We received two comments from the Aerospace Industries Association
(AIA) and the General Aviation Manufacturers Association (GAMA)
requesting that the provision be retained. First, they argued that as
in the past, a new aircraft may be produced at a commercial facility
that is destined for immediate conversion to a military only
application at a separate facility. These aircraft may require a small
number of airworthiness flight tests before being delivered to the
conversion facility and conceivably would be subject to EPA standards
during flight testing. While these aircraft would generally utilize
compliant engines, it may be possible that non-compliant engines could
be used (our standards do not apply to engines used on military
aircraft as discussed later) and temporary exemptions would be
necessary. Second, AIA and GAMA commented that it would be helpful if
the provision also allowed for granting a discrete number of exemptions
over a specified time period, rather than having to request the
exemption prior to each flight as currently required.
In considering the commenters' suggestion to retain the exemption
provision, we note that allowing such operations will not have any
significant adverse affect on the environment because of the infrequent
nature and short duration of such flights. Retaining the exemption is
also consistent with exempting military aircraft from emission control
requirements as discussed later. Therefore, we have retained the
provision with one change, made in response to the comments, as
described below.
The current provision calls for the Secretary of Transportation to
consult with the EPA Administrator when considering any exemption
request for infrequent interval and short duration flights not
explicitly allowed by the regulations. Given the inconsequential nature
of such flights on the environment, we believe that the Secretary
should be able to consider and act on these petitions unilaterally to
streamline the process. Therefore, we are deleting that portion of the
previous exemption provision. Of course, we will consult with the
Secretary if asked to do so. As for requesting a discrete number of
temporary exemptions, we believe this is an issue that the Secretary of
Transportation may address under its enforcement role as described in
section 232 of the CAA.
The current regulations also provide for permanent exemptions for
newly-manufactured engines based on consideration of the certain
factors specified in section 87.7(c). We are replacing these provisions
with new regulatory text generally consistent with the ETM that would
provide for permanent exemptions or exceptions \83\ for newly
manufactured engines used on new aircraft and spare engines used for
maintenance or replacement purposes. These are summarized below. (See
Sec. 87.50 of the regulations for additional details on these
exemptions/exceptions.)
---------------------------------------------------------------------------

\83\ As used in 40 CFR part 87, as a practical matter the
meanings of ``exception'' and ``exemption'' are essentially
equivalent. However, under FAA regulations, the meanings of these
terms are distinct, especially with respect to the manner in which
they are administered.
---------------------------------------------------------------------------

a. New Provisions for Spare Engines
We are revising the regulations to allow the sale of a newly-
manufactured engine for installation on an in-service aircraft, i.e., a
spare engine that does not conform to the applicable emissions
standards at the time it was produced. It does not allow for installing
such an engine on a new aircraft. Spare engines are produced from time
to time in order to keep an aircraft in revenue service when the
existing in-service engine must be removed for maintenance or
replacement purposes as needed. Otherwise removing these aircraft from
active service would be very expensive and logistically difficult.
As we explained in the proposal, explicitly allowing for the
production of spare engines is not addressed in the existing
regulations because there is no production cutoff for the current Tier
4 NOX standards. Thus manufacturers have been allowed to
continue production of older engine designs under type certificates
first issued before the Tier 4 standards took effect (e.g., Tier 2).
However, final regulations now apply a Tier 6 NOX production
cutoff to all newly- manufactured engines. This means that if we did
not also adopt a provision for the continued production of spare
engines, manufacturers would be prohibited from producing Tier 4
engines under the existing type certificates for this purpose. We see
no reason to change our policy of allowing manufacturers to

[[Page 36361]]

produce new engines for use as spares. Therefore, the final regulatory
provisions allow this practice to continue.
To ensure there would be no adverse environmental effect from
allowing the use of a spare engine as a direct replacement for an
existing engine, we proposed that the spare could be used only when the
emissions for all pollutants of that engine were equal to or lower than
those of the engine it replaced. This proposed requirement was
consistent with the ETM, which also contains this allowance. We
received a joint comment from AIA and GAMA stating that this is
impractical because, while unlikely, a spare engine might have a
different emissions profile for some pollutants than the engine it
would replace. As an example, they stated that the two engines could
have somewhat different combustion systems that might make one engine
lower in NOX but higher in CO. They also suggested that EPA
should consider the totality of the emissions in the decision, or
delete the requirement in the final rule.
These comments are surprising because this ETM provision, as well
as the exception provisions, was subject to significant discussions
within CAEP that included the engine manufacturers as well as a
representative from AIA. Nonetheless, in this instance we believe the
proposed provision should be modified to accommodate the potential for
unusual circumstances as explained by the commenter.
As noted above, AIA and GAMA suggested that EPA consider of the
totality of emissions relative to their environmental effects as the
basis for evaluating spare engine exemptions. This would entail
understanding and comparing the environmental consequences of the
different pollutants. We find that could be very complicated because
different pollutants have different health and welfare end points and
consequences. For example, in the illustration offered by the
commenters, the effects of LTO NOX and CO are largely
unrelated to one another.
We think a preferred option to evaluating total environmental
effects, or even dropping the provision entirely, is to incorporate an
anti-backsliding requirement which ensures that at a minimum the
excepted spare engine at least meets the same emission standards that
are applicable to the engine it is replacing. For this reason, in
response to the AIA and GAMA comment, we are modifying this provision
in the final rule to allow an excepted spare engine to have different
emission levels compared to the engine it replaces as long as it
remains compliant with each of the applicable emission standards and
any other requirements of its type certificate. Given the limited
number of spare engines in the fleet, we expect allowing these engines
to have somewhat different emissions profile from engines they are
replacing will have no significant adverse environmental effect. This
is especially true given that we expect the emissions of an excepted
spare engine will be equal or better than the engine it is replacing in
most cases in accordance with the basic tenant of the ETM.
We are not requiring engine manufacturers to obtain FAA or EPA
approval before producing spare engines. However, they must submit
information about the production of spare engines in an annual report
to EPA (see section III. D for more on the annual report). We proposed
that because manufacturers are not required to seek or obtain formal
approval to produce spare engines, this allowance was referred to as an
``exception'' rather than an ``exemption''. This terminology would be
consistent with current FAA regulations. Furthermore, we proposed that
the permanent record for each engine excepted under this provision
would need to indicate that the engine is an excepted spare engine and
the engine itself would need to be labeled as ``EXCEPTED SPARE.'' in
accordance with FAA marking requirements of 14 CFR.
We received comments relating to allowing spare engines to be
produced without requiring prior approval and the use of the terms
``exceptions'' or ``excepted.'' The Air Transport Association (ATA)
\84\ appreciated that there would be no case-by-case approval, noting
that it simplifies administering the provision for FAA without
compromising the structure of the exemptions program set forth in the
ETM. Regarding the terminology, AIA and GAMA noted that the terminology
was inconsistent with current engine name plate labeling practices.
They stated that engines are currently either marked ``COMPLY'' or
``EXEMPT'' for emissions. Both organizations generally felt the change
in terminology for spare engines might be concerning to the operators
holding an engine with a plate reading ``EXCEPTED.'' They concluded
that the name plate for spare engines should continue to use
``exempt.'' The ATA appeared to give at least tacit approval to the new
terminology by acknowledging without objection that spare engines would
be labeled accordingly.
---------------------------------------------------------------------------

\84\ The Air Transport Association has changed its name to
Airlines for America (A4A).
---------------------------------------------------------------------------

First, we are puzzled that operators with a spare engine labeled as
``excepted spare'' rather than ``exempt'' may have a concern, because
AIA and GAMA did not elaborate on just what the concern might be.
Without at least an example, we are unable to discern the nature of the
concern and respond directly to it. We also find it puzzling that the
two organizations that represent aerospace manufacturers expressed a
concern regarding operators of aircraft and aircraft engines when the
actual organization representing those companies, ATA, did not express
such a concern.
Second, regarding the terminology, the Tier 6 production cutoff
does not apply to the continued production of engines that are
designated spares. Spare engines are produced to replace a similar
engine already in service that was removed from service for maintenance
purposes. Accordingly, the production of a spare engine is not
restricted by the production cutoff, and the regulation does not apply
to these engines. The non-applicability of the cutoff eliminates the
need to process an exemption for continued production of these engines
beyond December 31, 2012.
Conversely, engines that are intended to be produced for new
installations (i.e. not replacing an engine already in service) are
subject to the production cutoff regulation and the continued
production of such engines beyond the cutoff date would require a grant
of exemption. Since the production of spare engines is not subject to
the new cutoff regulations, the FAA proposed and the EPA accepted the
idea that referring to these engines as exceptions to the regulation
was more appropriate than requiring case-by-case consideration of
exemptions when the regulation did not apply.
Moreover, the word ``exemption'' is a meaningful regulatory term.
It is used by the FAA in 14 CFR Part 11 to mean that an applicant is
subject to a particular regulation and is requesting time-limited
relief under a specific set of criteria. It is a specialized form of
rulemaking. When an entity or its product is specifically left out of a
regulatory provision, it is considered ``excepted''. Any regulation
adopted by the FAA would use these terms consistently.
As already mentioned, assuming incorporation of these provisions by
the FAA, engines meeting the requirements for spare engines could be
produced and entered into commerce without prior approval from EPA or
FAA. It is

[[Page 36362]]

important to note that while spare engines would be excepted from the
Tier 6 NOX standards being promulgated today, they still
need to be produced under an FAA type certificate. (This FAA oversight
would serve the same role as the exemption approval step envisioned by
ICAO in its ETM language for spare engines.) We also expect minimal
additional burden for manufacturers, since we are not establishing new
restrictions, monitoring, recordkeeping, or reporting requirements
other than the end of year report.
b. New Provisions for Engines Installed in New Aircraft
The primary purpose of allowing limited continued production of
Tier 4 engines is to provide for an orderly implementation of the Tier
6 NOX production cutoff. It addresses engines reaching the
end of their production cycles in the time frame when new emission
standards take effect. The typical production cycle would have annual
production volumes ramp up quickly, remain at relatively large volumes
for several or many years, and then fall off over a few more years.
When new emission standards are adopted in the middle of a production
cycle to take effect a few years later, manufacturers generally devote
technical resources to bring into compliance those engine models
expected to be produced in large numbers in the time frame when the new
standards are in effect. In contrast, they may plan not to invest in
upgrading the emissions of engine models that would be very near the
end of their normal production cycles when compliance with the new
standards becomes required. The actual length and shape of this tail of
production volumes can be affected by factors not fully within the
engine manufacturers' control, e.g., unexpected market demand. Thus,
exemptions may be justified if a manufacturer does not complete the
production cycle before the production cutoff date and projected
production volumes are not adequate to justify investing the necessary
resources to reduce emissions or there are other technological issues.
Furthermore, in certain exceptional circumstances exemptions may
also be appropriate. These are ``hardship'' situations that may arise
as a result of unforeseen technical or economic circumstances or events
beyond control of the manufacturer. For example, this could vary from
unexpected problems with technology upgrade programs to labor
disruptions or natural events disrupting production or parts
availability.
Our regulations currently address these kinds of situations in
section 87.7(c), entitled, ``Exemptions for New Engines in Other
Categories.'' We are replacing this provision with a new set of
provisions addressing exemptions for new engines.
i. Time Frame and Scope
The final regulations allow engine manufacturers to request an
exemption for newly-manufactured engines not meeting the Tier 6
NOX standards so they may be installed in new aircraft. If
granted, manufacturers may produce a limited number of these newly-
manufactured engines in a four year time period beginning after
December 31, 2012 and going through December 31, 2016. This four-year
time period is consistent with the ETM. The period for any given
approved exemption could be shorter depending on the specifics of the
application, but it could not be longer. This exemption limits
NOX emissions from engines that are covered by a valid type
certificate issued by FAA. The engines must meet all other applicable
requirements. More specifically, an engine exempted from the Tier 6
NOX standards must be covered by a previously issued type
certificate showing compliance with the Tier 4 NOX
standards,\85\ as well as the current HC, CO, fuel venting, and smoke
standards.
---------------------------------------------------------------------------

\85\ Engines certified only for compliance with earlier Tier 2
NOX standards would not be eligible for exemptions. This
is also consistent with the exemption language in the ICAO ETM. Note
that where such engines have emissions actually meeting the Tier 4
NOX standard, they may be recertified to the Tier 4
standards, but only before the effective date of the regulations.
---------------------------------------------------------------------------

As explained above, the scope of the exemption provisions are
limited to newly-manufactured engines that do not comply with the Tier
6 NOX standards. No need has been identified to apply such
exemption language to the other regulated exhaust pollutants, i.e.,
smoke, hydrocarbons and carbon monoxide. The emission standards for
those pollutant species have remained unchanged for nearly three
decades and present no technical issues for modern turbofan
engines.\86\ If new emission standards for these pollutants are
considered in the future, the potential need for exemption provisions
will also be assessed at that time.
---------------------------------------------------------------------------

\86\ For example, the hydrocarbon exhaust emission standards
were adopted on December 30, 1982. See 47 FR 58462.
---------------------------------------------------------------------------

We received comments requesting that exemptions be available for
newly-certified engines in addition to newly-manufactured engines.
General Electric Aviation (GE) stated that unforeseen circumstances may
arise during the lengthy aircraft engine development process that
necessitates a change in design, and that may affect the ability of
that engine model to meet the prevailing Tier emission standard at
certification. For that reason, GE concluded that exemptions for newly-
certified engine would be beneficial. The AIA and GAMA jointly stated
that the existing 40 CFR 87.7(c) not only provides the flexibility to
exempt newly-manufactured engines from a production cutoff, but also
for newly-certificated engine models subject to any emission standards,
e.g., the Tier 8 NOX standards. They requested that this
flexibility should be retained.
Regarding the availability of exemptions for newly-certified engine
models, the proposed regulatory text made clear that the exemption
provisions would only apply to newly-manufactured engines.
Specifically, the intent was to establish provisions for newly-
manufactured engines to address the potential technology and economic
adversities that may arise as part of adopting the Tier 6 production
cutoff. The ICAO ETM provisions are clearly intended for that same
purpose. Also, the original intent of EPA's current exemption
provisions in Sec. 87.7(c), which we are modifying in this rulemaking,
is clear from the proposed rulemaking and final rulemaking that
resulted in those provisions. The March 24, 1978 proposal described the
concern as ``* * * engines which are nearly [at] the end of their
production life would be terminated prematurely because there would be
insufficient future sales to justify incorporating emission controls.''
(See 43 FR 12619, March 24, 1978.) The December 30, 1982 final rule
referenced ``* * * the removal of an engine model from the market
because of its failure to comply.'' (See 47 FR 58468, December 30,
1982.) Obviously, the intent of the existing exemption provision cited
by AIA and GAMA was to make it apply only to newly-manufactured
engines.
As a general matter, we believe an exemption from the Tier 6
standard, or any other standard, for newly-certified engine models is
speculative at this time and would undermine the goal of regulatory
compliance by new engine designs. In any event, neither the current
ICAO Annex 16, Volume II provisions nor the ETM provide for newly-
certified engine exemptions. We believe that such would be a
fundamental shift from Annex 16 and the ETM should be explored within
the framework of ICAO/CAEP. Furthermore, engine manufacturers already
have

[[Page 36363]]

significant leadtime between the date CAEP adopts a new emission
standard and the standard's effective date, e.g., usually 3-5 years.
Finally, engine manufacturers historically design new engine models to
comply with the most stringent future standard that also provides for a
longer development time horizon. Therefore, we are promulgating the
exemption provisions for newly-manufactured engines as proposed.
ii. Production Limit
As proposed, Sec. 87.5 of the final regulations reflect the
essence of the general exemption language for exhaust emission
standards regarding how to determine the number of allowable exemptions
that is embodied in existing Sec. 87.7(c) of the regulations. That
provision generally that the FAA, with EPA's concurrence, may grant
exemptions to exhaust emission standards based on factors such as
adverse economic impact on the engine manufacturer, aircraft
manufacturer, or airline industry; in addition to the effects on public
health and welfare.
As a result, Sec. 87.5 does not specify a nominal number of
exemptions. Rather, each request for exemption would be evaluated on a
case-by-case basis, using the information provided by the applicant and
any other relevant information that is available to FAA and EPA at the
time. Any approved exemption would include a specific limit on the
number of such engines based on that information and is not defined on
a basis such as type certificate. (See section III.B.b.iii for a
description of what the request must contain.) The intent, of course,
would be to exempt the minimum number of engines that can be clearly
justified, including a consideration of the public health and welfare
effect associated with the exemptions.
In the proposal, we acknowledged that our approach to determining
limits on the number of exempt engines differs from the language
contained in the current ICAO ETM guidance. The ETM states that ``[t]he
number of engines exempted would normally not exceed 75 per engine type
* * *.'' \87\ We chose not to propose adopting this language on the
nominal number of engines based on a single type certificate. Our
reasons for this deviation were detailed in the. The interested reader
is referred to the proposed rule for more detail. (See 76 FR 45012.
July 27. 2011.) We also want to emphasize that the exemption provisions
as proposed and promulgated in this notice are not necessarily limited
to the Tier 6 NOX production cut-off, but could in fact be
applied to future aircraft engine emission standards if a similar
production cut-off was adopted. Therefore, we believe our approach is
preferable because it more clearly leaves the number of exemptions that
might be granted open, not limited to either more or less than 75 per
engine type, and subject to the justification supplied by the engine
manufacturer, both for the Tier 6 production cut-off and the future.
---------------------------------------------------------------------------

\87\ CAEP/8--WP/18, Environmental Technical Manual (ETM), Vol.
II on the Use of Procedures in the Emission Certification of
Aircraft Engines, Appendix ``ICAO Emissions Environmental Technical
Manual''.
---------------------------------------------------------------------------

We received several comments focusing primarily on the number of
exemptions and the underlying process that is embodied in the ETM and
our proposal. General Electric Aviation (GE) maintained that
harmonization with the international community is not only required by
the Chicago Convention, but also provides streamlined processes and
procedures within the regulated industry. They contended that any
purported benefits to EPA's unique exemption scheme were outweighed by
setting up a conflict with the remainder of the world. They also
suggested that if EPA wants a different approach for evaluating
exemptions, it would be more appropriate to work inside the ICAO/CAEP
process toward that end.
The ATA commented that EPA's case-by-case approach to determining
the number of engines is a rejection of the ICAO/ETM provisions that
limit ``* * * the number of exemptions * * * to 75 engines per type
certificate * * *.'' They argued that this would create a serious
discontinuity between the U.S. and the rest of the world, undermining
ICAO's objective of international uniformity. The ATA also argued that
the ICAO exemption limits are intended to be coordinated among
international aviation authorities, and that differing rules would make
this impracticable. As evidence of this problem, ATA cited the European
Aviation Safety Agency's (EASA) proposed rulemaking, which they noted
was based on the assumption that the ICAO proposals will be adopted
unaltered by other aviation authorities of the world. The ATA also
stated that the ICAO ETM guidance document supplements the official
standards of Annex 16, Vol. II and, therefore, the ETM provides
technical elaboration on the implementation of Annex 16. From this ATA
concluded that differing practices in this regard are counter to the
Chicago Convention.
Regarding consistency with the Chicago Convention, our proposal
thoroughly explained that the ETM is guidance material; not an ICAO
standard or regulation of any type. While consistency is desirable, it
is not compelled when a deviation is justified. Therefore, we disagree
with the commenters on this point, and specifically with ATA's comment
that the ICAO guidance is effectively the equivalent of an ICAO Annex
16 standard.
Turning to ATA's comment regarding the ETM cap of 75 engines per
type certificate, we first want to point out that this is not a maximum
limit on the number of potential exemptions per type certificate nor is
it an implied entitlement. Rather the ETM provision is an expectation
that ``[T]he number of engines exempted would normally not exceed 75
per engine type certificate * * *.'' as stated in the document. With
this perspective both the ETM and our approach are similar in that the
maximum number of exempted engines is based on a consideration of the
petitioner's justification for such exemptions.
Finally, we disagree with the comment that the differences with the
ETM make international coordination unworkable. In fact, one of the
proposed justification elements, i.e., how many affected aircraft will
be registered in the U.S. and other countries (estimate allowed), was
described in the preamble for the proposal as being aimed at helping to
facilitate consultation and coordination. Also, as noted above, the
ETM's expectation and our approach are similar in that the maximum
number of exempted engines under both approaches is based on a
consideration of the petitioner's justification for such exemptions. We
do not think coordination with foreign aviation authorities, with these
few differences, should pose any problems. After considering the above
comments on the number of exemptions and the underlying process
embodied in the ETM and our approach, we are promulgating the
provisions relating to the comments as originally proposed.
iii. Exemption Requests
We are establishing a process for requesting exemptions (for
engines used on new aircraft) that would be more formal and structured
than the current process. We are requiring manufacturers submit their
request to the FAA, as currently required. The FAA will then share the
submittal with EPA and execute the consultation process.
To ensure that we have the information necessary to evaluate
exemption requests in this specific manner, the requests need to
include the following details to describe the specific engine model for
which the manufacturer is requesting the

[[Page 36364]]

exemption. The final provisions contained in Sec. 87.50, which are
summarized below, are consistent with and in some areas expand on the
provisions in the ETM:
General Information
Corporate name and an authorized representative's contact
information (including a signed statement verifying the information);
Description of the engines for which you are requesting
the exemption, including the engine model and sub-model names;
The number of engines that you would produce under the
exemption and the period during which you would produce them;
Identify the authorizing type certificate (type
certificate number and date);
Information about the aircraft in which the engines will
be installed, including the airframe models and expected first
purchasers/users of the aircraft, and the countries in which you expect
the aircraft to be registered (including an estimate of how many will
be registered in the U.S.); and
List of other certificating authorities from which you
have requested (or expect to request) exemptions, and a summary of each
request.
Justification and Impacts Assessment
A detailed description and assessment of the environmental
impact of granting the exemption;
Technical issues, from an environmental and airworthiness
perspective, which may have caused a delay in compliance with a
production cutoff, if any;
Any economic impacts on the manufacturer, operator(s), and
aviation industry at large; and
Projected future production volumes and plans for
producing a compliant version of the engine model in question.
Other Factors
Hardship: Impact of unforeseen technical circumstances,
business events, or other natural or manmade calamities beyond your
control, and
Equity issues in administering the production cutoff among
economically competing parties.
It is important that any action on a potential exemption request be
in the public interest; the fairly comprehensive list of application
information in the regulations is intended to gather the information
needed for this assessment. We would expect to take a broad perspective
in evaluating what is or is not in the public interest. This is why a
manufacturer's justification needs to include a quantified description
of the environmental effects of granting the exemption, as well as
discussion of economic and technical issues related to bringing the
engine into compliance. The analysis of environmental impacts needs to
specify by how much the exempted engines would exceed the standards,
the in-use effects in terms of lifetime tons of NOX, and
estimate the emissions rates of engines/aircraft that could potentially
be used if the exemption was not granted. Since exemptions granted
under the regulations apply only to NOX emissions, the
analysis could also include possible benefits regarding noise levels or
reduced emissions of pollutants other than NOX. Relevant
economic impacts could include effects on the engine manufacturer,
airframe manufacturer, airline(s), and the general public.
As we detailed in the proposal, some manufacturers have requested
exemptions in the past based on the largest number of engines they
hoped to continue manufacturing without knowing how many they would
actually be able to produce or who would purchase them. The new
exemption language calls for manufacturers to target their requests
more specifically based on likely production needs and time periods.
While we expect a manufacturer to have this specific information when
they submit a request, the final regulations allow us to process
exemption requests with somewhat less specific information. However, we
expect this to apply only for unusual circumstances. Manufacturers also
are being required to notify the FAA if they determine after submitting
a request that the information is not accurate, either from an error or
from changing circumstances.
The final regulations also allow manufacturers to revise their
requests to justify covering additional engines at any time before
approval. We would then review the revised request. Similarly, for
exemptions that are already approved, manufacturers could request that
additional engines be added after providing the justification for the
increase.
We received comments on the level of detail required in a request
for exemption and the time needed to add more engines to such a request
or an already approved exemption. First, ATA was concerned that
requesting an increased amount of engine exemptions can take a
significant amount of time. They stated that there may be insufficient
time for a manufacturer to receive approval for additional engine
exemptions if necessary to meet previously unknown market demands.
In response, we find it unfortunate that the comment does not
provide a specific example or other information that may illustrate
this concern. As a general response, given the long leadtime between
the initiation of discussions among aircraft purchasers and aircraft
manufacturers, and actual orders and final deliveries, we expect that
manufacturers will have enough time to request additional engine
exemptions, and if appropriate, for the FAA and EPA to approve such a
request. We expect that amending an already approved exemption would
take less time to act upon than the original petition. Also, engine
manufacturers may request an expedited review from the FAA, and by
association the EPA, if circumstances warrant. Finally, to the extent
that an engine manufacturer has specific concerns in this area, they
could be ameliorated by improving the lines of communication with air
frame manufacturers to increase the manufacturer's awareness of market
interest in potential new orders. Accordingly, we are promulgating the
exemption provision relating to this comment as proposed.
Second, ATA commented negatively that the exemption request for
each individual engine be justified, ``* * * including the exact
number, initial purchasers/users, countries of registry and plans for
bringing the product into compliance.'' They claimed that this
knowledge may not be known at the time of the exemption request because
of market leadtime. As an example, ATA cited the 1998 Rolls Royce (RR)
exemption request from the CAEP/2 cutoff for 150 engines that was not
based on that type of certainty, but was a prospective exemption for
two years as protection against the uncertainties of technical
development. They stated that RR did not know when the development
process would be completed, and hence did not know the exact number of
non-compliant engines that airlines would purchase. The ATA also added
that the three affected airlines worked with RR to provide
documentation of the financial and operational hardship that they would
suffer based on their aircraft delivery schedules.
In response to ATA's second comment, we simply want to note that
the information we would normally expect to be contained in the
exemption application is actually not much different than the
justification envisioned by the ETM. That guidance document explains
that the petitioner should, to the extent possible, provide
quantitative support to justify the

[[Page 36365]]

exemptions. Specifically, the ETM states that it ``* * * provides
guidelines on the process and criteria for issuing exemptions * * *.''
These include some of the same elements as contained in our proposal
and referenced above, i.e., the exact number of exemptions being
requested, to whom the engines will be originally delivered, and plans
for producing a compliant product. Therefore, the ETM envisions a
consideration of specific information as part of the exemption request,
in a similar fashion as EPA's approach, in order to decide on the exact
number of exemptions to grant. We are simply being more explicit in
some areas concerning the type of information that should be included
in any exemption request. We also note ATA's comment that ``[T]he
airlines worked with Rolls Royce to provide documentation of the
financial and operational hardship that they would suffer if there were
an interruption in the supply of ICAO-compliant engines during their
aircraft delivery schedules.''
Given the long lead times generally associated with new aircraft
orders and deliveries, we expect aircraft operators will work closely
with aircraft manufacturers as their new aircraft needs are identified.
Engine manufacturers should in turn work with aircraft manufacturers to
stay aware of market interest in potential new orders. This appears to
be reflected in the commenter's example regarding the cooperation
between airlines and RR in fashioning the exemption justification.
Also, as explained in the proposed regulatory text, the petitioner
should include information on the ``expected'' first purchasers/users
of the aircraft. It also asked for information on the number of
aircraft that will be registered in the U.S. versus other countries and
that this may be estimated, if not known. Therefore, precise knowledge
is not needed for certain elements of the justification. The preamble
to the proposed requirements also stated that the regulations would
allow us to process exemption requests with somewhat less specific
information, although we expected that to apply only for unusual
circumstances. We have made this clearer in the final regulations.
In order to allow us to oversee these exempted engines,
manufacturers are being required to also provide an annual report to
EPA on exempt engines similar to the information about spare excepted
engines. The permanent record for each engine exempted under this
provision must indicate that the engine is an exempted engine and the
engine itself must be labeled as ``EXEMPT NEW.''
iv. Coordination of Exemption Requests
The limit on the number of potentially exempt engines as described
in the ETM is intended to apply to overall worldwide production. Toward
that end, the ETM envisions that certificating authorities and member
states should coordinate whenever any authority receives an exemption
request.
Working with the FAA, we expect to consult with other aviation
authorities whenever we receive an exemption request. This would
include a consultation with other certificating authorities as well as
coordination with the appropriate civil aviation authority of any
country where the aircraft with the exempted engines will be
registered.
To facilitate this coordination, we are asking that manufacturers
also include in their requests, a list of countries in which the
aircraft are expected to be registered. While not specifically listed
in the ETM, we believe that this information is consistent with the ETM
as it would be necessary to ensure proper coordination. The ETM appears
to presume that each member country will recognize exemptions granted
by other countries. This presumption seems reasonable assuming that the
exemption being granted is generally consistent with the guidelines of
the ETM and that the consultation and coordination called for in the
ETM was conducted in good faith. However, there should be no
presumption that EPA would agree to an exemption for an engine model if
the aforementioned collaboration, consultation, and coordination were
not conducted. The Clean Air Act (which provides EPA with its authority
to establish emission standards) includes no provisions that would
allow any foreign country or other certificating authority to exempt
subject aircraft engines, over the objection of FAA and EPA, from the
applicable standards EPA promulgates.\88\ Nevertheless, because our
final exemptions provisions are generally consistent with the
procedures called for in the ETM, assuming appropriate consultation and
coordination in accordance with the ETM and absent unforeseen
complications, it is reasonable to believe that FAA and EPA would not
object to exemptions for engines properly exempted by other countries
under those procedures. The FAA would still need to take the
certification action as called out in 14 CFR 91.203 and 14 CFR 21.183.
---------------------------------------------------------------------------

\88\ It is possible that applications for exemptions by foreign
entities may be filed with their national certificating authorities
for engines manufactured after December 31, 2012 and could be
operated in the United States. The FAA has several international
bilateral agreements in place that include provisions and
obligations for technical assistance on environmental certification
matters. The FAA plans to continue to coordinate with those foreign
certificating authorities in their considering and granting
petitions for exemptions and, likewise, those that are filed with
the FAA and in consultation with EPA.
---------------------------------------------------------------------------

This, however, raises the question as to how we would respond to an
exemption request when another certificating authority did not consult
or coordinate on a previous request for the same engine model. A
related concern arises if an FAA type certificate is sought under a
reciprocity agreement for an engine which was previously certificated
under an exemption by a foreign certificating authority, and the
original exemption was not coordinated with the United States. Such
requests would likely be viewed as new exemption requests if the
anticipated collaboration, consultation, and coordination had not
occurred.
Thus to avoid these issues, in most cases, manufacturers may want
to work with all relevant certificating authorities at the same time as
well as the civil aviation authority of nation(s) where the aircraft
will be initially registered or operated if that nation requires a type
certificate issued under its own regulations to operate in its air
space consistent with international agreements.
v. Low-Volume, Time-Limited Transitional Exemption Program
We received a comment from one manufacturer expressing concern that
once the final rule becomes effective additional time may be required
for EPA and FAA to establish and undertake procedures to review and act
upon exemption requests. They stated that the time needed for this
process could be very disruptive for engine manufacturers that have
already contracted to delivery engines during the period which FAA/EPA
would need to consider exemption requests. They also claimed it would
be harmful to airplane manufacturers and airlines. To avoid such an
undesirable outcome, the commenter suggested that EPA should grant a
one-time, interim block of perhaps 20 exemptions.
Based on supplemental information we received from the
commenter,\89\ we find the concerns center on six engines for which
they have contract commitments to build and deliver within several
months of this final rule. These six engines belong to two engine
models, with four engines in one model

[[Page 36366]]

and two engines in the other. The first model consisting of four
engines is scheduled to begin shipping in January 2013, shortly after
the January 1, 2013 Tier 6 production cut off. These engines are
currently certificated to the Tier 4 NOX standards. The
commenter has stated, however, that the design of this engine model has
been technically modified to achieve the Tier 6 standards.
Unfortunately, compliance testing of this model to meet the Tier 6
standards cannot be performed until December of 2012 when the first
production version is built. Assuming that this testing is successful,
inadequate time remains for the FAA to formally recognize Tier 6
compliance based on those tests before the production cutoff becomes
effective.\90\ The two new aircraft using these engines are being built
and will be delivered to a foreign airline.
---------------------------------------------------------------------------

\89\ Memoranda documenting this supplemental information are
located in docket number EPA-HQ-OAR-2010-0687.
\90\ The FAA has stated to EPA that inadequate time exists for
the required formal compliance determination before the production
cutoff takes effect.
---------------------------------------------------------------------------

The second model is comprised of two engines with a contracted
delivery date in May 2013. They are also certificated to the Tier 4
NOX standards. These engines are at the end of their
production life, i.e., no additional future deliveries for civilian
uses are anticipated beyond these two contracted engines. For this
reason, the commenter has stated that it is not economically feasible
to redesign this model to conform with the Tier 6 NOX
standards, even if it were technically feasible. The single new
aircraft using these engines is also being built for delivery to a
foreign airline.
After assessing this concern, we are including an exception
provision in the regulations that permits any aircraft engine
manufacturer to produce and enter into commerce up to six newly-
manufactured engines with a date of manufacture, as defined in the
regulations, prior to August 31, 2013 that are not certificated to meet
Tier 6 emission requirements. We find that a considerable amount of
time will indeed be required between the time this final rule becomes
effective and completing any formal FAA action using the normal
exemption process as previously described in this notice. Specifically,
time is needed for: (1) The FAA to amend 14 CFR part 34 through
rulemaking to incorporate the production cutoff and procedures for
granting exemption from the new standards; (2) the manufacturer to
develop the information needed to support a request; (3) submitting the
request for review by FAA and EPA; (4) coordination with other
certificating authorities; and (5) EPA and FAA review and final action
on the request, i.e., approval or disapproval. Regarding this review
and final action, we note that FAA staff involved in reviewing the
manufacturers request may also be engaged in conducting the processes
to adopt this rule in 14 CFR part 34 and to review emission information
on current type certificates to confirm that they meet either Tier 6 or
Tier 8 requirements, as previously described. Therefore, we conclude
that inadequate time exists to act on an exemption request with
certainty for these six engines before their contract deliver dates.
Consequently, we conclude that a limited modification to the otherwise
universal effective date of the final Tier 6 compliance deadline is
appropriate to accommodate the commenter's situation and that for these
six specific engines additional lead time is needed due to cost and
technical feasibility factors.
We also believe that disrupting the scheduled delivery dates of
these engines could risk subjecting the commenter to possible financial
penalties for late delivery, with possible follow-on effects for the
aircraft manufacturer and airlines. We also find that there is no
significant adverse effect on the environment in allowing these six
engines to be produced and sold as compliant with Tier 4 standards,
especially if four of the engines ultimately comply with the Tier 6
standards.
For the above reasons, and in response to the comments and under
our authority under sections 231(a)(3) and (b) to issue final
regulations with such modifications to the proposal as the
Administrator deems appropriate and to make revised standards effective
after such period as the Administrator finds necessary to permit the
development and application or requisite technology, giving appropriate
consideration to the cost of compliance within such period, we are
including an exception provision in the regulations that permits any
aircraft engine manufacturer to produce and enter into commerce up to
six newly manufactured engines with a date of manufacture, as defined
in the regulations, prior to August 31, 2013 that are not certificated
to meet Tier 6 emission requirements. These engines must have a type
certificate which indicates that they meet the 40 CFR part 87
requirements last updated on October 30, 2009 (i.e., Tier 4). No formal
exemption request or approval will be required for these six engines.
These engines will be reported to EPA as part of the annual reporting
requirement as described above for exempt engines.
We know of no other engine manufacturer that is in this situation
today, (i.e., contracted deliveries of engines not meeting the
production cut-off within several months of the production cut-off
date). However, as a matter of equity and to address situations which
we may not be informed of at this time, we are extending this
transitional flexibility to all manufacturers.
c. Voluntary Emission Offsets
We requested comment on establishing a voluntary EPA program by
which manufacturers could receive emission credits for producing
cleaner engines, which they could use to offset higher emissions from
exempted engines. An example of such a program was summarized in a
memorandum to the docket.\91\ The types of programs we were considering
would be developed, promulgated, and administered by EPA.
---------------------------------------------------------------------------

\91\ U.S. EPA, ``Draft Regulatory Text for Voluntary Offset
Program,'' Memorandum from Charles Moulis, Assessment and Standards
Division, Office of Air Quality and Transportation, June 2011. A
copy of this document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

As described in the proposal and summarized here, we expected
manufacturers to be interested in generating offsets for one of three
purposes. First, manufacturers might choose to generate offsets as part
of their justifications for exemptions. Second, manufacturers might
choose to generate offsets as part of a justification for being allowed
to exceed the numerical limit that FAA and EPA are willing to approve
in an exemption request. Third, provided a provision was promulgated to
allow this, a manufacturer might also be interested in generating
offsets to bank for use for exemptions of engines to be produced after
the credit generating engines are produced, or possibly against a
future production cutoff.
Under the proposed approach, generation of offsets would be
voluntary and would be open to all certifying engine manufacturers. One
concept was to allow credits to be generated only from engine models
that are introduced after this rule and that had characteristic levels
significantly below the otherwise applicable standard (e.g., at least
10 percent below). There was a separate question, however, regarding
how to calculate the credit. If we adopted, for example, a 10 percent
threshold for eligibility, we would probably also allow credits only to
the degree which the NOX characteristic level was more than
10 percent below the standard.

[[Page 36367]]

This would ensure a net improvement in emissions. Also, we could
reserve the right to restrict the use of credits so that they were used
in a manner that ensured there was no net adverse impact on air
quality. Such a program would need to ensure that emission benefits
from one aircraft model truly offset the higher emissions from another
model. Equivalency factors could be developed to account for
differences in the number of LTOs per year and the lifetime of the
aircraft.
We received a number of comments on the possibility of implementing
a voluntary credit offset program. The ATA expressed significant doubt
that EPA had the legal authority to adopt a voluntary emissions offset
program. They argued that the standard setting authority under section
231 of the CAA does not appear to provide such authority. ATA further
stated that where offsets or emissions trading schemes exist for other
source categories, the authority is express. Examples cited were the
CAA authority for the trading program under the acid rain program, and
the Energy Independence and Security Act authorization for the offset
program used under the Corporate Average Fuel Efficiency Standards.
Pratt & Whitney provided comments very similar to ATA relative to the
lack of EPA's legal authority to create such a program.
The ATA also commented that the voluntary offset program embodied
in the proposal would be unworkable in the context of aviation. They
noted that unlike cars or trucks, aircraft engine manufacturers have
relatively low production volumes and few frequently updated models for
generating credits. Also, some manufacturers have more models than
others and this could possibly lead to competitive distortions in the
market. The AIA and GAMA also raised concerns regarding potential
market disruptions. Further, ATA argued that opportunities for
generating offsets would be limited by the proposal's high thresholds
for generating those credits. In the context of using emission credits
for exemptions ATA added that each situation would be unique and it
would not be possible to match exemptions to credits, or to assess the
further complexities of the ``equivalency factors'' described in the
proposal. Finally, they stated that an airline's delivery schedule
would be held hostage to the manufacturer's ability to justify credits
based on some other engine that the airline is not buying. For these
reasons, ATA asked that no offset program be adopted.
Pratt & Whitney stated that the EPA proposal assumes that an offset
program would create an incentive for manufacturers to build lower-
emissions engines. On the contrary they argued, manufacturers already
have that incentive because using the lowest-emitting technology that
is available maximizes the life of the engine. Such a program would
simply create a windfall to manufacturers whose product lines are
already capable of generating credits. The AIA, GAMA, and GE jointly
commented that the proposed emission offset program goes beyond the
borders of CAEP, and any emissions offset program should be developed
within ICAO. General Electric was interested in exploring a potential
emission offset program, particularly if the program would be
applicable to new engine designs and derivatives that are subject to
the proposed Tier 8 standards, and if it created the incentive to adopt
new technologies earlier than would otherwise be the case in the
absence of such incentives.
We appreciate the concerns raised by the commenters regarding the
proposed voluntary offset emission program. We are also encouraged by
GE's interest in further discussions about how this program may be
useful in the context of the Tier 8 standards and a possible future
Tier 8 production cutoff. EPA agrees that the proposal needs to be
further developed to address certain aspects of the offset program. We
have determined that the time it would take to sufficiently develop the
program is incompatible with the need to promptly promulgate the Tier 6
production cutoff standard with a near-term effective date of January
1, 2013. Therefore we are not including the voluntary emission offset
program in the final rule at this time. Nonetheless, we continue to see
value in such a program for the aviation industry and recommend
continuing to consider such a regulatory flexibility in the future.
Although we are deferring action on the proposed voluntary emission
offset program for the time being, we believe that such programs are
envisioned within the ETM language related to exemptions. Furthermore,
we do not agree with the commenters who questioned the EPA's legal
authority for adopting a voluntary emissions offset program as part of
the aircraft engine emission standards. We are somewhat surprised by
the industry commenters who questioned the authority for averaging,
banking, and trading (ABT) programs outside of the narrow examples
cited in their comments, and we are not yet persuaded by their claims.
Note that the U.S. Court of Appeals for the D.C. Circuit has clearly
stated that EPA has substantial discretion under the CAA section 231 to
adopt final aircraft emission standards as the agency deems appropriate
(National Ass'n of Clean Air Agencies v. EPA 489 F.3d 1221 (D.C. Cir.
2007)). We also wonder to what extent their view represents the
industry as a whole, including any aircraft engine manufacturers who
also manufacture engines that are subject to other EPA regulations that
provide for ABT without the ``express'' statutory authority the
commenters claim is necessary. If in future actions we seek additional
comments on the legality of ABT programs under our aircraft standards,
we will be interested in receiving comments from other stakeholders in
the mobile source arena who might have views regarding the arguments
presented by the industry commenters above.
In the meantime, we note that several of our mobile source
regulations, in addition to the rule cited by industry commenters, have
long provided regulated industry with the flexibilities inherent in an
ABT program, under the authority of, for example CAA section 213, and
none of those subject industries have opposed the creation of such
programs or questioned their legal basis. (See, e.g., 40 CFR part 89,
subpart C (averaging, banking and trading provisions for nonroad
compression-ignition engines); 40 CFR part 90, subpart C (certification
averaging, banking and trading provisions for nonroad spark-ignition
engines at or below 19 kilowatts); 40 CFR part 91, subpart C
(averaging, banking and trading provisions for marine spark-ignition
engines); 40 CFR part 92, subpart D (certification averaging, banking
and trading provisions for locomotives and locomotive engines); 40 CFR
part 94, subpart D (certification averaging, banking and trading
provisions for marine compression-ignition engines).) EPA continues to
believe that the legal basis of these ABT programs is sound.
4. Potential Phase-In of New Tier 8 NOX Standards for Newly-
Manufactured Engines
We did not propose a production cutoff for the Tier 8
NOX standards for newly-manufactured engines. This means
that engine manufacturers may continue to produce Tier 6 compliant
engines of previously certified models after the Tier 8 standards
become effective for newly-certified engine models. As noted elsewhere,
EPA is working within the ICAO/CAEP framework to develop harmonized
international standards for aircraft

[[Page 36368]]

turbine engines. At the February 2010 meeting of CAEP, where the CAEP/8
NOX standards were approved for recommendation to ICAO, the
committee decided that further consideration could be given to a
related newly-manufactured engine standard pending new information on
technology and market responses, although no formal action was taken at
the time to explicitly make this a future work item for CAEP.\92\
---------------------------------------------------------------------------

\92\ ICAO, ``Committee on Aviation Environmental Protection
(CAEP), Report of the Eighth Meeting, Montreal, February 1-12,
2010,'' CAEP/8-WP-80. A copy of this document is in docket number
EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

Assuming a CAEP/8 production cutoff is adopted at some time in the
future, we will re-examine the permanent exemption provisions to ensure
a timely and orderly phase-out of engine models that do not meet the
CAEP/8 NOX standards. We would expect this to be done
through a notice and comment rulemaking process to amend our own
regulations.

C. Application of Standards for Derivative Engines

It is very common for a manufacturer to make changes to an
originally type certificated engine model that is in production while
keeping the same basic engine core and combustor design. In some cases
these modifications may affect emissions. As a result, the
certificating authority (in our case the FAA) must decide whether the
emission characteristics of the modified design were significant enough
from the parent engine's certification basis that a demonstration of
compliance with more recent emission standards is necessary, or if the
changes were minor relative to the parent engine's emission
certification basis so that it is considered a derivative version of
the original model with no emissions changes. This may be further
complicated because of the common practice of making iterative changes
over time raises the question as to when the cumulative changes reach a
point where a new demonstration of compliance is warranted.
In the past, these determinations were made for turbofan engines by
an engineering evaluation that was performed by the engine manufacturer
and then reviewed by the FAA. As part of the ICAO/CAEP deliberations
leading up to the February 2010 CAEP/8 meeting, a new standardized
guidance was agreed upon as described in the ETM. The guidance, which
the U.S. fully supported, includes specific criteria that can be used
to determine when a design modification requires a new demonstration of
compliance with newer emission standards, or when a modification was
simple enough to be considered a no emissions change.
We are including the ETM requirements in our regulations to address
the longstanding need to provide consistent standards for the decision
process regarding derivative engines and applicable emission standards.
The definition of ``derivative engines for emissions certification
purposes,'' along with the criteria for making this determination, will
provide engine manufacturers and the regulators with more certainty
regarding emission standard requirements for future modifications made
to certificated models. To ensure that the numerical decision criteria
can be administered to allow for the consideration of unusual
circumstances or special information, we are also providing the FAA
with some flexibility to make adjustments to the specific criteria
based on good engineering judgment. In summary, if the FAA determines
that an engine model is sufficiently similar to its parent engine so as
to meet the criteria established in Sec. 87.48, the manufacturer may
demonstrate certification compliance and continue production of the
engine model to the same extent as allowed for the original engine
model. However, if the FAA determines that an engine model is not a
derivative for emission certification purposes, the manufacturer would
be required to demonstrate compliance with the most recent emissions
standards. This determination will be made using numerical criteria
consistent with ICAO provisions, and a modified engine model can be
considered a ``derivative'' only if it is: (1) Derived from an original
engine that had received a U.S. certification, (2) the original engine
was certified under title 14 of the CFR, and (3) one of the following
conditions is met:
(1) The FAA determined that a safety issue exists that requires an
engine modification; or
(2) Emissions from the derivative engines are equivalent to or
lower than the original engine.
The proposed rule provided that the engine manufacturer could show
emissions equivalency by demonstrating that the difference between
emission rates of a derivative engine and the original engine are
within the following allowable ranges, unless otherwise adjusted using
good engineering judgment as determined by the FAA:

3.0 g/kN for NOX
1.0 g/kN for HC
5.0 g/kN for CO
2.0 SN for smoke

The proposed rule also provided that engine models represented by
characteristic levels at least five percent below all applicable
standards would be allowed to demonstrate equivalency by engineering
analysis. In all other cases, the manufacturer would be required to
test the new engine model to show that its emissions met the
equivalency criteria.
We received three significant comments on the proposed derivative
provisions. First, ATA, PW, and Dassault-Aviation (DA) pointed out that
the proposed criteria contained a substantial deviation from the
expressed intent of the proposal and the ETM guidance. Specifically,
they noted that the ETM provides that ``If a modified engine remains on
the existing type certificate, it may retain the existing certification
basis of the parent engine if the modification(s) * * * results in a
decrease of the absolute emissions levels. * * * '' They pointed out,
however, that the proposed rule provided that the certificate holder
must demonstrate `` * * * the proposed derivative engine model's
emissions meet the applicable standards and differ from the original
model's emission rates only within * * * '' specified ranges for each
pollutant. For example, the specified range is + or-3 g/kN for
NOX. The commenters stated that this is more stringent than
the ETM, and could discourage cleaner engines that are not clean enough
to meet the next tier of standards. They asked that the final rule be
consistent with the ETM to prevent this untoward effect.
We agree that the regulations should allow for such engines to be
considered derivatives, even if the difference was outside the ``no
emission change'' range. This allowance is clearly consistent with the
ETM and was inadvertently left out of our proposed language. Therefore,
the final regulations contain this allowance.
Second, AIA and GAMA jointly commented that the term ``new model''
was inappropriate when used to determine which engine models could
demonstrate equivalency by engineering analysis, and when the
manufacturer would be required to test the new engine model to
demonstrate compliance with the equivalency criteria. They argued that
because this provision applies to changes made to an existing engine,
it could cause an engine manufacturer to conduct an additional
emissions test in cases where a very small change was made to the
engine

[[Page 36369]]

due to a performance or engine weight change. The commenters
recommended that this be altered to allow a manufacturer to consider
``* * * such emissions changes by analysis prior to this point, and
only if such analysis revealed a deterioration that pushed the engine
very close to the emission limits that the manufacturer be requested to
complete an engine emissions test.''
The AIA and GAMA also jointly commented on the proposed regulatory
text that states if the characteristic level of the original
certificated engine model before modification is at or above 95 percent
of the applicable standard for any pollutant, you must measure the
proposed derivative engine model's emissions for all pollutants to
demonstrate the derivative engine's resulting characteristic levels
will not exceed the applicable emission standards. They claimed that
the use of the term ``you must measure'' also implies further engine
testing when additional analysis may likely prove sufficient.
We agree that the term ``new model'' should be modified and have
instead used the term ``new engine configuration'' in the final
regulations. We want to clarify, however, that the regulations do
explicitly require engine testing when an original engine's emissions
are within 5 percent of any emission standard. This text does not allow
engineering analysis in such cases. We continue to believe this to be
the appropriate policy. Given the greater uncertainty of engineering
analysis relative to actual testing, we cannot rely on it for engines
very close to the standard. This provision is also consistent with the
ETM. Therefore, we are promulgating this requirement as proposed.
Third, AIA, GAMA, and GE commented that as a general matter, EPA
should not codify the ETM's derivative engine decision criteria because
the ETM guidance will evolve over time and the Agency's rigid
regulations will not, even allowing for the FAA flexibility to use good
engineering judgment if necessary when deciding what is or is not a
derivative engine. They concluded it was simply better to let the FAA
rely on the ETM guidance in its decision making. As noted by the
commenters, the ICAO ETM itself is a guidance document for use by
aviation authorities. It does not represent a standard or any other
enforceable regulatory requirement. In the particular case cited by the
commenters, they appear to ask that FAA be given unlimited discretion
to determine which engines are subject to each new tier of standards.
In response to the comment, we also note that the Clean Air Act
directs EPA to establish air pollution emission standards for aircraft
engines. (See 42 U.S.C. 7551(a)(2)(A).) Implementation of this
statutory directive mandates that we specify enforceable air pollution
emission standards and control requirements for aircraft engines in
regulatory form. We believe that it is reasonable for us to also
establish other associated requirements in regulatory form. Our final
rule achieves an appropriate balance between providing FAA discretion
to implement the standards, and the need to establish aircraft engine
emission regulations that ensure consistency in application.
We also disagree with the suggestion that the ETM will evolve over
time, but that our regulations will not. As a working member of ICAO's
Committee on Aviation Environmental Protection, we will participate in
developing any relevant revisions to the ETM and will make appropriate
adjustments to our regulations as needed.
We continue to believe that the ETM specifications for ``no
emissions change'' are appropriate objective criteria for derivative
engines. Thus, because we are codifying regulatory provisions to
objectively specify when engines are considered to be ``derivative
engines'', we are promulgating regulatory provisions consistent with
the ICAO ETM guidance.

D. Annual Reporting Requirements

In May of 1980, ICAO's Committee on Aircraft Engine Emissions
(CAEE) recognized that certain information relating to environmental
aspects of aviation should be organized into one document. This
document became ICAO's ``Annex 16 to the Convention on International
Civil Aviation, International Standards and Recommended Practices,
Environmental Protection'' and was split into two volumes--Volume I
addressing Aircraft Noise topics and Volume II addressing Aircraft
Engine Emissions. Annex 16 has continued to grow and today Annex 16,
Volume II includes a list of mandatory requirements to be satisfied in
order for an aircraft engine to meet the ICAO emission standards.\93\
These requirements include information relating to engine
identification and characteristics, fuel usage, data from engine
testing, data analysis, and the results derived from the test data.
Additionally, this list of aircraft engine requirements is supplemented
with voluntarily reported information which has been assembled into an
electronic spreadsheet entitled ``Emissions Databank'' (EDB) \94\ for
turbofan engines with maximum thrust ratings greater than 26.7 kN in
order to aid with emission calculations and analysis as well as help
inform the general public.
---------------------------------------------------------------------------

\93\ ICAO, ``Annex 16 to the Convention on International Civil
Aviation, Environmental Protection, Volume II, Aircraft Engine
Emissions,'' Part III, Chapter 2, Section 2.4. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.
\94\ United Kingdom, Civil Aviation Authority, ``ICAO Emissions
Databank.'' Available at the Civil Aviation Authority Web site
www.caa.co.uk/default.aspx?catid=702.
---------------------------------------------------------------------------

In order to understand how current gaseous emission standards are
affecting the current fleet, we need to have access to timely,
representative emissions data of the engine fleet at the requisite
model level. The EDB is a useful tool for providing a general overview
of the aircraft fleet, as it contains information on engine exhaust
emissions and performance tests. However, it is not updated on a
consistent basis, it contains a varying amount of voluntarily reported
data from each manufacturer, and it does not specifically list every
engine sub-model.\95\ It also does not contain information on smaller
thrust category turbofans or turboprops, and contains no information on
past or recent engine production volumes. We need this data to conduct
accurate emission inventories and develop appropriate policy.
Accordingly, we do not consider the EDB to be a sufficient tool upon
which to base policy decisions or adopt future standards. Furthermore,
in the context of EPA's standards-setting role under the Clean Air Act
with regard to aircraft engine emissions, it is consistent with our
policy and practice to ask for timely and reasonable reporting of
emission certification testing and other information that is relevant
to our mission. Under the Clean Air Act, we are authorized to require
manufacturers to establish and maintain necessary records, make
reports, and provide such other information as we may reasonably
require to discharge our functions under the Act. (See 42 U.S.C.
7414(a)(1).)
---------------------------------------------------------------------------

\95\ Under today's regulations, a grouping of engines with an
essentially identical emission-related design are defined to be an
``engine sub-model''. Engines with slightly different designs are
defined to be an ``engine model''.
---------------------------------------------------------------------------

Therefore, we proposed to require that each aircraft engine
manufacturer submit a production report directly to EPA \96\ with
specific information for each individual engine sub-model that: (1) Is
designed to propel subsonic aircraft, (2) is subject to our exhaust
emission standards, and (3) has received

[[Page 36370]]

a U.S. type certificate. More specifically, the scope of the proposed
production report would include turbofan engines as described above
with maximum rated thrusts greater than 26.7 kN, i.e., those subject to
gaseous emission and smoke standards. In addition, it would include
turbofans with maximum rated thrusts less than or equal to 26.7 kN and
all turboprop engines, i.e., those only subject to smoke standards. We
also proposed that this specific exhaust emission related information
be reported to us in a timely manner, which will allow us to conduct
proper emissions inventory analyses of the existing fleet and to ensure
that any public policy we create based on this information will be well
informed. All of the specific reporting items we proposed were the same
as requested for the EDB, with the exception of total annual engine
production volumes, information on type certificates, and the emission
standards to which the engine sub-model was certified. We anticipated
that the new emissions database would be a significant improvement over
the current EDB because the data reporting is mandatory, it will be
comprehensive in that it covers all engine models, and it must be
updated annually.
---------------------------------------------------------------------------

\96\ The report would be submitted only to EPA. No separate
submission or communication of any kind is required for the FAA.
---------------------------------------------------------------------------

In addition to some minor comments which are addressed in the
analysis of comments document, we received comments from engine
manufacturers addressing two specific areas of the proposed production
reporting provision. First, the Aerospace Industries Association (AIA),
General Aviation Manufacturers Association (GAMA) and Pratt & Whitney
(PW) commented that annual production volume data is considered
confidential business information (CBI) and as such, it should be
exempt from Freedom of Information Act (FOIA) requests or other methods
of public disclosure. Second, AIA, GAMA, PW and Williams International
pointed out that for those engines which are only subject to smoke
standards (turbofans with maximum thrust ratings less than or equal to
26.7 kN, and turboprops), manufacturers are not required under current
regulations to measure gaseous emissions (HC, CO, NOX,
CO2). As such, data on these gaseous emissions, as well as
information used to measure gaseous emissions (reference pressure ratio
and fuel flow data) are not readily available for these engines.
Further, smoke data by mode of the LTO cycle may not be available for
these older engines. These manufacturers pointed out that new testing
of such engines would be required to generate these data, and that
appropriate test procedures for these engines do not currently exist.
We understand and respect the needs of manufacturers to maintain
the confidentiality of their legitimately proprietary data. However, we
do not include in our regulations an up-front blanket CBI determination
for any of the other mobile source sectors, and do not believe it is
necessary here. As such, in response to the comments, we are including
regulatory language patterned after existing regulations for several
other mobile source categories which sets forth how we would treat--on
a case by case basis--submitted data which is covered by a CBI claim
from the manufacturer as provided by 40 CFR part 2. The addition of
this provision will ensure that no information that is legitimately
protected CBI gets inadvertently released to the public.
We do not believe it is appropriate to require additional testing
for turbofans with maximum thrust ratings less than or equal to 26.7 kN
and turboprops specifically for production reporting purposes. Thus,
for these engines, we will not be requiring the submission of HC, CO,
NOX, CO2, reference pressure ratio or fuel rate
data. Further, we will not require additional testing of older engines
for which smoke data by specific LTO cycle segment is not currently
available.
We also noted in the proposal that the reported information would
be used in conjunction with the NOX and CO2
emission data already required to be submitted to us under section
87.64 for purposes of greenhouse gas (GHG) reporting to establish. This
would effectively provide us with a complete and comprehensive engine
exhaust emissions database. We noted our expectation that most
manufacturers would likely add the proposed information items to the
annual GHG report. No comments were received on combining the two
reports. After further deliberation, we have decided to require a
single, integrated report in this final rule to eliminate any possible
confusion regarding the two separate reports and make reporting more
efficient.
The incremental reporting elements for each affected gas turbine
engine sub-model are listed below. Although not proposed, we have added
engine type to the list for completeness. The reporting elements of the
existing GHG report are also identified for completeness.
Company corporate name as listed on the engine type
certificate (GHG);
Engine Type (turbofan, mixed turbofan, or turboprop);
Calendar year for which reporting (GHG);
Complete sub-model name (This will generally include the
model name and the sub-model identifier, but may also include an engine
type certificate family identifier) (GHG);
The type certificate number, as issued by the FAA (Specify
if the sub-model also has a type certificate issued by a certificating
authority other than the FAA) (GHG);
Date of issue of type certificate and/or exemption, i.e.
month and year (GHG);
Emission standards to which the engine is certified, i.e.,
the specific Annex 16, Volume II, edition number and publication date
in which the numerical standards first appeared.
If this is a derivative engine for emissions certification
purposes, identify the original certificated engine model.
Engine sub-model that received the original type
certificate for the engine type certificate family;
Production volume of the sub-model for the previous
calendar year (even if zero). If an engine sub-model is no longer being
produced, state that the engine sub-model is not in production and list
the date of manufacture (month and year) of the last engine produced;
Regarding the above production volume report, specify (if
known) the number of engines that are intended for use on new aircraft
and the number intended for use as certified (non-exempt) spare engines
on in-use aircraft;
Reference pressure ratio (GHG) (not applicable to
turbofans with maximum thrust ratings less than or equal to 26.7 kN,
and turboprops);
Combustor description (type of combustor where more than
one type available on an engine);
Engine maximum rated thrust output, in kilonewtons (kN) or
kilowatts (kW) (depending on engine type) (GHG);
Unburned hydrocarbon (HC) mass (g) total (weighted) and
over each segment of the Landing and Take-off Cycle (LTO), i.e. Take-
off, Climb, Approach, Taxi/Ground Idle (not applicable to turbofans
with maximum thrust ratings less than or equal to 26.7 kN, and
turboprops);\97\
---------------------------------------------------------------------------

\97\ See Regulation Part 87--Control of Air Pollution from
Aircraft and Aircraft Engines, Subpart E, Sec. 87.42 Production
report to EPA for definitions.
---------------------------------------------------------------------------

Unburned hydrocarbon (HC) characteristic level (i.e. mass
of hydrocarbons over LTO cycle/Rated Thrust (Dp/Foo)) (not applicable
to turbofans with maximum thrust ratings less than or equal to 26.7 kN,
and turboprops);\98\
---------------------------------------------------------------------------

\98\ Dp/Foo: total gross emissions of each gaseous pollutant
(mass)/rated thrust (g/kN).

---------------------------------------------------------------------------

[[Page 36371]]

Carbon monoxide (CO) mass (g) total (weighted) and over
each segment of the entire Landing and Take-off Cycle (LTO) (i.e. Take-
off, Climb, Approach, Taxi/Ground Idle) (not applicable to turbofans
with maximum thrust ratings less than or equal to 26.7 kN, and
turboprops);
Carbon monoxide (CO) characteristic level (i.e. mass of CO
over LTO cycle/Rated Thrust (Dp/Foo)) (not applicable to turbofans with
maximum thrust ratings less than or equal to 26.7 kN, and turboprops);
Nitrogen oxides (NOX) mass (g) total (weighted)
and over each segment of the entire Landing and Take-off Cycle (LTO)
(i.e. Take-off, Climb, Approach, Taxi/Ground Idle) (GHG) (not
applicable to turbofans with maximum thrust ratings less than or equal
to 26.7 kN, and turboprops);
Nitrogen oxides (NOX) characteristic level
(i.e. mass of NOX over LTO cycle/Rated Thrust (Dp/Foo))
(GHG) (not applicable to turbofans with maximum thrust ratings less
than or equal to 26.7 kN, and turboprops);
Smoke number total and over each segment of the entire
Landing and Take-off Cycle (LTO) (i.e. Take-off, Climb, Approach, Taxi/
Ground Idle), if available;
Smoke number characteristic level;
Carbon dioxide (CO2) mass (g) total (weighted)
and over each segment of the entire Landing and Take-off Cycle (LTO),
(i.e. Take-off, Climb, Approach, Taxi/Ground Idle (GHG)) (not
applicable to turbofans with maximum thrust ratings less than or equal
to 26.7 kN, and turboprops);
Number of tests run per sub-model (GHG);
Number of engines tested per sub-model (GHG);
Fuel flow (grams/second) total (weighted) and over each
segment of the Landing and Take-off Cycle (LTO) (i.e. Take-off, Climb,
Approach, Taxi/Ground Idle) (GHG) (not applicable to turbofans with
maximum thrust ratings less than or equal to 26.7 kN, and turboprops);
and
Any additional remarks to the EPA.
The annual report is required to be submitted for each calendar
year in which a manufacturer produces any engine subject to emission
standards as previously described. These reports will be due by
February 28 of each year, starting with the 2014 calendar year, and
cover the previous calendar year. This report shall be sent to the
Designated EPA Program Officer. Where information provided for any
previous year remains valid and complete, the engine manufacturer may
report the production figures and state that there are no changes
instead of resubmitting the original information. To facilitate and
standardize reporting, we expect to specify a particular format for
this reporting in the form of a spreadsheet or database template that
we provide to each manufacturer. As noted previously, we intend to use
the reports to help inform any policy approaches regarding aircraft
engine emissions that we consider, including possible future emissions
standards. The information will also enhance the general public's
understanding of the emission characteristics of aviation gas turbine
engines and allow independent development of emission inventories and
assessments of local environmental effects. Subject to the applicable
requirements of 42 U.S.C. 7414(c), 18 U.S.C. 1905, and 40 CFR part 2,
all data received by the Administrator that is not confidential
business information may be posted on our Web site and will be updated
annually. We have assessed the potential reporting burden associated
with this annual reporting requirement. That assessment is presented in
sections V. and IX.B of this notice.

E. Standards for Supersonic Aircraft Turbine Engines

We proposed CO and NOX emission standards for turbine
engines that are used to propel aircraft at sustained supersonic
speeds, i.e., supersonic aircraft to complement our existing HC
standard for these engines. These standards were originally adopted by
ICAO in the 1980s, and our adoption of NOX and CO standards
for commercial engines in 1997 omitted coverage of these pollutants for
supersonic commercial engines that were then in use. The lack of EPA CO
and NOX standards for engines used by supersonic aircraft
has had no practical effect, because no such engines have been
certified by the FAA. Also, none of the engines used on these aircraft
are currently in production.
The Aerospace Industries Association (AIA) and the General Aviation
Manufacturers Association (GAMA) commented that within CAEP it was
agreed that these standards are ``not appropriate for future products''
and should not be adopted by EPA.\99\ However, to meet U.S. treaty
obligations under the Convention on International Civil Aviation as
previously described in section I.C, we believe it is necessary and
appropriate to adopt these conforming standards. Therefore, we are
promulgating the standards for supersonic aircraft as proposed. As
previously noted, this action has no practical effect, and simply
aligns EPA standards with the rest of the world. (See section III.G for
a brief discussion of potential revised emission standards for future
engine designs that may be used on supersonic aircraft.)
---------------------------------------------------------------------------

\99\ The CAEP position referred to by AIA and GAMA is based on
the expectation that future designs for supersonic aircraft will be
significantly different from past designs. The agreement was reached
at CAEP/8 to evaluate emission standards for these engines as a
future work item.
---------------------------------------------------------------------------

F. Amendments To Test and Measurement Procedures

We are incorporating by reference into the 40 CFR 87.60 regulatory
text, amendments to ICAO's International Standards and Recommended
Practices for aircraft engine emissions testing and certification.\100\
\101\ \102\ These amendments to Annex 16, Volume II are primarily
intended to ensure that the provisions reflect current certification
practices. The amendments make clarifications or add flexibilities for
engine manufacturers. They are described below.
---------------------------------------------------------------------------

\100\ A strikeout and highlighted version of the amendments is
contained in Attachment A to ICAO state letter AN 1/61.2, AN 1/62.2-
07/32 entitled, ``Proposed Amendment to International Standards and
Recommended Practices, Environmental Protection, Annex 16 to the
Convention on International Civil Aviation, Volume II Aircraft
Engine Emissions, May 27, 2007. A copy of this document is in docket
number EPA-HQ-OAR-2010-0687.
\101\ ICAO, ``International Standards and Recommended Practices,
Annex 16 to the Convention on International Civil Aviation,
Environmental Protection, Volume II Aircraft Engine Emissions,''
Third Edition, July 2008, International Civil Aviation Organization.
This document contains the full text of ICAO standards and practices
and is in docket number EPA-HQ-OAR-2010-0687.
\102\ ICAO, ``International Standards and Recommended Practices,
Annex 16 to the Convention on International Civil Aviation,
Environmental Protection, Volume II Aircraft Engine Emissions,
Amendment 7, effective July 18, 2011'' Third. A copy of this
document is in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

Standardizing the terminology relating to engine thrust/
power
Clarifying the need to correct measured results to
standard reference day and reference engine conditions
Allowing a certificating authority to approve the use of
test fuels other than those specified during certification testing
Allowing materials other than stainless steel in the
sample collection equipment
Clarifying the appropriate value of fuel flow to be used
at each LTO test point
Clarifying exhaust nozzle terminology for exhaust
emissions sampling
Allowing an equivalent procedure for gaseous emission and
smoke

[[Page 36372]]

measurement if approved by the certificating authority
Manufacturers are either already voluntarily complying with these
changes or will be even in the absence of a final rule. Our adoption of
these test procedure amendments is, therefore, unlikely to require new
action by manufacturers beyond what they have already done to meet
ICAO's adopted and recommended amendments.
Our incorporation by reference of the ICAO test procedure makes
most of the existing subpart G and all of subpart H of part 87
obsolete. Therefore, we are removing these sections from the
regulation, as proposed.

G. Possible Future Revisions to Emission Standards for New Technology
Turbine Engines and Supersonic Aircraft Turbine Engines

As a general matter, emission standards not only apply to all
conventional turbofan aircraft engines greater than 26.7 kN, but also
to all aircraft engines designed for applications that otherwise would
have been fulfilled by turbofan aircraft engines. The high price of jet
fuel, current emphasis on fuel economy, and need to reduce emissions
have renewed interest in open rotor propulsion designs for future
aircraft gas turbine engines. Essentially, the fan of an open rotor
engine is not contained within an engine nacelle as it is with a
conventional turbofan engine. This design has also been referred to as
an unducted fan, propfan, or ultra-high bypass engine. At least two
engine manufacturers are actively pursuing such designs for
certification in the later part of this decade.
It now appears that certain aspects of EPA's gas turbine engine
emission standards may be incompatible with these new designs. For
example, the current landing and takeoff cycle for emissions
certification is based on conventional engine designs where a
significant amount of thrust is generated by an idling engine.
Specifically, idle emissions are measured and calculated at seven
percent of the engine's rated thrust. However, the fan/prop blades of
an open rotor engine may be variable in pitch and this may allow the
blades to be ``feathered'' at idle. In that position, the blades are
rotated so very little thrust is generated as the engine idles and
generates emissions. Also, future aircraft using these engine designs
may fly at somewhat slower speeds. This might affect the time these
aircraft spend during the climbout mode of the landing and takeoff
cycle. Therefore, the traditional landing and takeoff cycle used in
turbofan engine emissions certification may need to be revised in the
future to accommodate open rotor engines.
We will be working within CAEP to evaluate the differences between
conventional turbine engine and open rotor engine technologies, and to
revise the emission standards and test procedures as appropriate for
these latter engines. If any changes are required, EPA will undertake
rulemaking to revise our regulations accordingly.
There may also be changes in the emission standards and test
procedures for engines used to power future supersonic transport
aircraft designs. The emission standards for these engines were
originally developed in the early 1970s in response to the
Aerospatiale-BAC Concorde. Since that time, there have been varying
levels of interest in developing a new generation of supersonic
transport. As a result, the current CAEP work program is evaluating the
status of supersonic aircraft engine development and the potential need
for new emission standards and test procedures.\103\ Our recent
discussions with engine manufacturers indicate that no substantive work
is being undertaken at this time, however. We will continue to work
within CAEP on this issue and undertake rulemaking to revise the
regulations for supersonic aircraft engines as appropriate.
---------------------------------------------------------------------------

\103\ The CAEP Working Group 3 has taken the position that
engine development programs for future supersonic aircraft
applications should be focused on achieving the emission standards
that are applicable to subsonic aircraft engines. Past supersonic
aircraft engines required the use of afterburner technology to
achieve supersonic speeds. Future supersonic aircraft are expected
to use engines without that technology, making them more similar to
their subsonic counterparts.
---------------------------------------------------------------------------

V. Description of Other Revisions to the Regulatory Text

In addition to the changes discussed above, we are including a
number of other changes to the regulatory program. Most of these
changes are designed to bring the program into conformity with current
technology and current technical or policy practice. Each of these is
discussed below.

A. Applicability Issues

This section discusses how this final rule relates to engines used
in military and noncommercial civilian aircraft. We do not believe
these changes will have practical significance for current engine
models because the changes align with manufacturers' current practice
in certifying their engines.
1. Military Engines
We do not intend today's action to have any impact on engines
installed on military aircraft, or new aircraft that are destined to be
converted for military use. Military aircraft are not required to have
FAA standard airworthiness certificates, and our 1997 endangerment
finding for NOX and CO emissions and resulting standards did
not cover military aircraft (see 62 FR at 25359). As such, engines used
in military aircraft are not required to meet EPA emission standards,
since our current regulations define ``aircraft'' subject to our rules
as any airplane for which a U.S. standard airworthiness certificate (or
foreign equivalent) is issued. (See 40 CFR 87.1(a) of the existing
regulations.) Currently, manufacturers certificate some engine models
used in military aircraft with the FAA (with respect to emissions),
because these engine models also have commercial applications and have
to be certificated for such use. Our new standards and requirements
will continue to apply only to engines used in aircraft for which
standard airworthiness certificates are required, and thus are not
applicable to engines used in military aircraft. It is not our intent
to interfere with current practice with regard to engine models with
joint commercial/military applications to the extent such engines are
used in military aircraft. Although civilian aircraft applications of
all such engines would be subject to the new standards and production
cutoff, in the NPRM we proposed to include a statement in the
regulations to clarify that the proposed production cutoff would not
apply for previously certificated engines that are installed and used
in military aircraft. One manufacturer commented that the definition of
``military aircraft'' we proposed should extend to sales of military
aircraft outside of the U.S. While we believe the regulations as
written do not apply to foreign sales of military aircraft, we are
nonetheless revising our proposed definition of ``military aircraft''
to clarify that foreign aircraft considered military under
international laws and agreements are not covered by 40 CFR part 87.
2. Noncommercial Engines
Prior to this action, section 87.21(d) specified that gaseous
emission standards applied to engines used in commercial applications
with rated thrusts greater than 26.7 kN. These are engines intended for
use by an air carrier or a commercial operator as defined in the
Chapter I, Title 49 of the United States Code and Title 14 of the Code
of Federal Regulations. Therefore,

[[Page 36373]]

engines of equivalent thrust ratings that are used in aircraft
certificated by the FAA that are used in non-revenue, general aviation
service were not required to comply with our current HC, CO, and
NOX exhaust emission standards in Sec. 87.21(d). They were
and are subject, however, to the current standards for smoke and fuel
venting.
In today's action we are applying the gaseous emission standards
for commercial engines to their noncommercial civilian counterparts
that are required to obtain standard airworthiness certificates. There
are a couple of reasons for this action. First, the ICAO Annex 16,
Volume II standards and recommended practices apply equally to
commercial and noncommercial engines, and our rules' previous failure
to reflect this meant that our requirements did not fully conform to
ICAO's standards. Second, manufacturers already emissions certify
engines that are used in non-revenue, general aviation service to these
standards. Therefore, this provision simply incorporates the status
quo.
In order to make EPA standards conform to ICAO's, we needed to, in
addition to promulgating the necessary regulatory amendments, update
the underlying finding regarding the need to limit gaseous emissions
from commercial and non-commercial civilian aircraft, pursuant to CAA
section 231(a)(2)(A). In 1997, our analysis and finding, and hence our
regulations, were limited to commercial aircraft emissions. (See 62 FR
at 25358.) In conjunction with the NPRM for this final rule, we
proposed to expand that analysis and finding to include gaseous
emissions from both commercial and non-commercial civilian aircraft
engines with rated thrusts greater than 26.7 kN. We received no
comments on that proposed finding, and are therefore finalizing our
emissions assessment supporting this finding, which is contained in the
docket for this rulemaking.\104\
---------------------------------------------------------------------------

\104\ U.S. EPA, ``Final Finding for Commercial and Noncommercial
Turbofan and Turbojet Aircraft Emissions,'' memorandum from John
Mueller, Assessment and Standards Division, Office of Transportation
and Air Quality, March 2012. A copy of this document is in docket
EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

B. Non-Substantive Revisions

We are also taking the opportunity to revisit the clarity of other
regulatory provisions in part 87. Many of these provisions were first
written 30 or 40 years ago with little or no change since then. We are
revising the text related to some of these provisions to better
organize, clarify, and update the regulations. Our goal is to revise
the regulations in part 87 to properly organize the content of the
regulation, use clearer language to describe the applicable
requirements, clarify some definitions, and clear up a variety of terms
and current practices that have not been adequately addressed.
Except as discussed in previous sections, the changes to part 87
are not intended to significantly change the certification and
compliance program. We did not reopen for comment the substance of any
part of the program that remains unchanged substantively.
This rule includes the following definitions and other minor
changes in addition to those changes described earlier in this section
or in section III.
The definition of the term ``aircraft'' is being revised to be
consistent with its meaning under FAA regulations in 14 CFR 1.1. The
existing part 87 definition limits ``aircraft'' to be only those
aircraft issued an airworthiness certificate. This was done as a way to
specify the applicability of the standards. However, this can cause
confusion in a variety of ways. For example, this departs from the
plain meaning of ``aircraft,'' as well as from the meaning given under
the Clean Air Act and Title 49 of the United States Code. The revised
definition aligns with these statutory definitions. The changed wording
is intended to clarify the existing policy without changing it.
Text specifying general applicability is being added to part 87.3
to be consistent with the new definition of ``aircraft'' and maintain
the effective applicability of the existing regulations, which uses
narrow definitions to limit applicability. For example, the existing
regulations limit the applicability of the standards by defining
``aircraft'' to only include fixed-wing airplanes with airworthiness
certificates. They exclude non-propulsion engines from the definition
of ``aircraft engine'' and turboshaft engines from the definition of
``aircraft gas turbine engine.'' We believe it is more appropriate to
explicitly exclude these engines in an applicability section than to
rely on readers finding these exclusions in the definitions section. We
are also renaming part 87.3 as ``General applicability and
requirements'' and reorganizing the content for clarity. Finally, we
are replacing the existing regulatory text related to federal
preemption for exempted engines in part 87.7(f) with a codification of
the statutory preemption language in part 87.3 and an explanatory note
that the statutory preemption applies to exempted engines because they
are certified to prior-tier standards.
ICAO Annex 16, Volume II is being incorporated by reference for
test procedures. This involves a broader reference to Annex 16, with
less content repeated in part 87. However, this does not substantively
change the test procedures that apply since the existing procedures are
based directly on Annex 16, Volume II. As part of this change, we are
adding the ICAO definition of ``characteristic level'' to properly
describe how manufacturers demonstrate that they meet applicable
standards.
Definitions are being added for ``date of introduction,'' ``date of
manufacture,'' and ``derivative engine for emissions certification
purposes,'' and the definition of ``engine model'' is being revised, to
more carefully describe when new emission standards apply to specific
aircraft engines. These definitions are generally consistent with the
most common understandings of these terms by industry and FAA, and with
the CAEP/8 recommendation for adoption by ICAO. Except for engines
subject to exemptions, there will be no more engines required to be
certified to the standards specified in part 87.21, so changing the
definition of ``engine model'' will not change the requirements for
engines certified to the Tier 4 or earlier standards. For the benefit
of the reader, we are also reprinting the following definitions that
remain unchanged:

Aircraft engine
Aircraft gas turbine engine
Class TP
Class TF
Class T3
Class T8
Class TSS
Commercial aircraft gas turbine engine
Fuel venting emissions

Specific provisions are being added to define and require the use
of ``good engineering judgment.'' This applies for instances where the
regulation cannot spell out every technical detail of how a
manufacturer should comply with the regulation. For example, the
regulations rely on good engineering judgment being used on the
engineering analysis of emissions equivalency for derivative engines
(part 87.48(b)(2)), and for applying the turbofan test procedures to
turboprop engines (part 87.60(a)). The general approach for
implementing good engineering judgment is to allow manufacturers to
exercise well substantiated and explained technical judgment subject to
potential EPA and FAA review (as appropriate). The consequences of
disagreements with a manufacturer's decision would depend

[[Page 36374]]

on whether we believe the manufacturer made the decision in good faith.
Where the manufacturer makes its decision in good faith, EPA or FAA
could require a different approach for future work if we believe it
would represent better engineering judgment. We believe these
provisions reflect the spirit of the approach being used today to
interpret the applicable regulations.
Provisions are being added specifying rounding practices for rated
output, rated pressure ratio, and calculated emission standards;
generally specifying that they be expressed to at least three
significant figures. The primary exception to this is the specification
that smoke numbers be expressed to one decimal place. These
specifications are consistent with how manufacturers are generally
certifying engines today. Defining how to round these values would
prevent manufacturers in the future from effecting small changes in the
level of the emission standards to which they certify their engines.
This is because standards are calculated using the numerical values of
the rated output and rated pressure ratio. Without these
specifications, manufacturers could subject themselves to a slightly
less stringent standard by selectively rounding or truncating an engine
model's rated output to be low and its rated pressure ratio to be high,
or by strategically rounding the calculated standard itself. While this
has not been an issue in the past, it is important to maintain a level
playing field for all manufacturers as standards become more stringent.
We do not expect any more engines type-certificated to the standards
specified in part 87.21, so the specified procedures for rounding these
values will not change the requirements for engines certified to the
Tier 4 or earlier standards
Definitions are being added for ``turbofan engine,'' ``turbojet
engine,'' ``turboprop engine,'' ``turboshaft engine,'' ``supersonic,''
and ``subsonic'' to avoid any uncertainty about how the standards apply
to different types of engines. The definitions are intended to reflect
the plain meaning of these terms.
The regulations include the following additional amendments:

------------------------------------------------------------------------
Description of
Regulation cite amendment Notes
------------------------------------------------------------------------
87.1....................... Add definition of The characteristic
``characteristic level is established
level''. by ICAO Annex 16 as a
means of calculating a
statistical adjustment
to measured emission
results to take into
account the level of
uncertainty
corresponding to the
number of tests run
for a given pollutant.
87.1....................... Remove definitions These terms will no
for ``emission longer be used in part
measurement 87. There will be no
system'', ``power more engines certified
setting'', to the standards
``sample specified in Sec.
system'', ``shaft 87.21, so removing
power'', ``taxi/ these definitions will
idle (in)'', and not change the
``taxi/idle requirements for
(out)''. engines certified to
the Tier 4 or earlier
standards.
87.1....................... Revise definition The new language
of ``exhaust references the
emissions'' and emission testing
``smoke''. procedures, since that
is the practical
meaning of these terms
in part 87. This
clarifies, for
example, that
emissions from the
nozzle of an aircraft
or aircraft engine
count as exhaust
emissions only if they
are measured using the
specified test
procedures. There will
be no more engines
certified to the
standards specified in
Sec. 87.21, so
revising these
definitions will not
change the
requirements for
engines certified to
the Tier 4 or earlier
standards.
87.1....................... Define ``new'' The regulations also
instead of refer to new turboprop
defining ``new engines and new
aircraft turbine engines used for
engine''. supersonic aircraft,
so it is appropriate
to define the
adjective as it
relates to these
different kinds of
engines. This approach
does not change the
meaning of the
applicable terms and
therefore has no
bearing on the
requirements that
applied under the
standards specified in
Sec. 87.21.
87.1....................... Revise the The editorial changes
definition of do not involve any
``standard day substantive change in
condition'': (1) the specified
Remove the conditions.
reference to the
1976 U.S.
Standard
Atmosphere, (2)
correct a
typographical
error in the
humidity
specification,
and (3) change
the atmospheric
pressure units
from Pa to kPa.
87.2....................... Remove FAA from This is intended to not
the list of involve a change in
acronyms in Sec. emission standards or
87.2 and add it implementation.
to the set of
defined terms in
Sec. 87.1.
87.3....................... Add provisions The broad statement in
describing the Sec. 87.3 is not
scope of intended to conflict
applicability of with the applicability
part 87. statements in
individual subparts,
since those additional
statements indicate
that certain
requirements in part
87 apply more
narrowly. All
applicability
statements in the rule
are intended to be
consistent with
current policy.
87.3....................... Remove the This change more
provision related carefully tracks the
to preemption of statutory provisions
state standards related to preemption.
for exempted
aircraft and
replace it with
the preemption
provision in the
Clean Air Act.
87.5....................... Move the This provision, and the
provisions similar provision from
related to Sec. 87.3(a), should
special test be described together
procedures to in the context of the
Sec. 87.60. testing requirements
in subpart G.
87.21...................... Identify the This corrects a
specific date typographical error
when the smoke from the Federal
standard started Register.
to apply for
turbofan engines
with rated output
less than 26.7
kilonewtons.
87.21...................... Revise paragraph This change is strictly
(f) to correctly editorial.
reference the
regulatory
sections that
describe the
applicable test
procedures.

[[Page 36375]]

87.60...................... Revise the There will be no more
description of engines certified to
test procedures the standards
to rely broadly specified in Sec.
on the procedures 87.21, so any changes
specified in ICAO to the test procedures
Annex 16. This will not change the
includes a requirements for
variety of recent engines certified to
changes to the the Tier 4 or earlier
Annex 16 standards. Moreover,
procedures. engine manufacturers
are expected to
perform all their
testing based on the
current test
procedures from ICAO
Annex 16, regardless
of the standards that
apply.
------------------------------------------------------------------------

C. Clarifying Language for Regulatory Text

The regulations incorporate the changes described in this preamble.
The following table highlights and clarifies several provisions that
may not be obvious to the reader.

------------------------------------------------------------------------
Regulation cite Note
------------------------------------------------------------------------
87.1, Definition of This definition would revert to the
``aircraft''. normal FAA definition of aircraft,
rather than the much narrower current
definition in part 87. To understand
this change, the definition needs to be
considered along with the changes to
applicability in 87.3(a).
87.1, Definition of ``date of This is generally the same definition as
manufacture''. given in ICAO Annex 16. However, our
definition addresses certain specific
circumstances that could possibly occur,
but that are not addressed by the Annex.
For example, our definition would
provide a date of manufacture for an
engine not previously documented by a
manufacturer.
87.1, Definition of It is important to consider this
``derivative engine for definition in combination with the
emissions certification definition of ``engine type certificate
purposes''. family''.
87.1, Definition of ``engine A manufacturer or FAA may further divide
model''. an engine model into sub-models. Engines
from an engine model must be contained
within a single engine type certificate
family. Where FAA determines that
engines are not sufficiently similar to
be included under a single type
certificate, they will not be considered
to be the same engine model for purposes
of part 87.
87.1, Definition of In Sec. 87.23(d) we clarify that the
``military aircraft'' and production cutoff does not apply for
87.23(d). military aircraft engines (even if they
have been certificated). In Sec. 87.1,
we define military aircraft to primarily
mean ``aircraft owned by, operated by,
or produced for sale to the armed forces
or other agency of the federal
government responsible for national
security (including but not limited to
the Department of Defense).'' For
example, aircraft owned by the U.S.
Coast Guard would be military aircraft.
In response to comments, we added a
clarification that military aircraft
also include ``other aircraft considered
to be military aircraft under
international law and conventions.''
87.1, Definition of The production cutoff date for the Tier 6
``production cutoff date''. NOX standards is December 31, 2012.
87.1, Definition of ``spare Newly manufactured spare engines may be
engine''. excepted under Sec. 87.50.
87.1, Definitions of tiers... As specified in the definitions of ``Tier
0'' through ``Tier 8'', tiers apply only
for NOX standards. Tiers do not apply
for HC, CO, and smoke standards because
these continue to apply, independent of
the NOX standards.
87.23(d)(2).................. The allowance to continue production of
Tier 6 engines after the Tier 8
standards start to apply is not
necessary for engines with rated
pressure ratio at or above 104.7 because
the Tier 6 and Tier 8 standards are
numerically identical at these thrust
levels.
87.42(c)(1).................. Sec. 87.42 requires that a manufacturer
report the engines it produces by sub-
model. The manufacturer must specify the
manufacturer's unique sub-model name,
which will generally include a model
name and a sub-model name. It may also
include a family name.
87.50........................ This provision specifies that EPA must
provide written concurrence for
exemptions.
87.50(a)(1)(iv)(F)........... This provision states that manufacturers
requesting exemptions should describe
equity issues. As an example of equity
issues related to an exemption request,
a manufacturer might provide a rationale
for granting the exemption when another
manufacturer has a compliant engine and
does not need an exemption, taking into
account the implications for operator
fleet composition, commonality, and
related issues in the absence of the
engine model in question.
87.50(a)(6).................. This provision requires manufacturers to
promptly notify the FAA if new or
changed information could have affected
approval of an exemption. For
corrections to an exemption request that
would not affect the approval of the
exemption, manufacturers may include the
updated information in the annual report
described in Sec. 87.50(e).
------------------------------------------------------------------------

VI. Technical Feasibility and Cost Impacts

During the CAEP process, the technical feasibility and cost of
compliance of the CAEP/6 and CAEP/8 NOX standards were
thoroughly assessed and documented.^{105 106} EPA participated
in these analyses and supported the results. Generally, CAEP considered
certain factors as pertinent to the cost estimates of a technology
level for engine changes, and these factors or technology levels are

[[Page 36376]]

described below. The first technology level was regarded as a minor
change, and it could include modeling work, minor design changes, and
additional testing and re-certification of emissions. The second
technology level was considered a scaled proven technology. At this
level an engine manufacturer applies its best-proven, combustion
technology that was already certified in at least one other engine type
to another engine type. This second technology level would include
substantial modeling, design, combustion rig testing, modification and
testing of development engines, and flight testing. The third
technology level was regarded as new technology or current industry
best practice, and it was considered where a manufacturer has no proven
technology that can be scaled to provide a solution and some technology
acquisition activity is required. (One or more manufacturers have
demonstrated the necessary technology, while the remaining
manufacturers would need to acquire the technology to catch up.) Since
the effective date for the CAEP/6 NOX standard was January
1, 2008 and nearly all in-production engines currently meet this
standard, we believe this clearly demonstrates the technical
feasibility of those standards. Therefore, we will limit our discussion
below to applying these technology levels to engines that need to
comply with the CAEP/8 NOX standard.
---------------------------------------------------------------------------

\105\ CAEP/6 NOX standards: CAEP Forecasting and
Economic Analysis Support Group, Economic Analysis of NOX Emissions
Stringency Options, CAEP/6-IP/13 (Information Paper 13), January 15,
2004. A copy of this document is in docket number EPA-HQ-OAR-2010-
0687.
\106\ CAEP/8 NOX standards: CAEP Working Group 3, NOX
Stringency Technology Response Assessment, CAEP-SG/20082-WP/18
(Working Paper 18), September 25, 2008. CAEP Forecasting and
Economic Analysis Support Group, Economic Assessment of the NOX
Stringency Scenarios, CAEP/8-IP/14, November 30, 2009. Modeling Task
Force, MODTF NOX .Stringency Assessment, CAEP/8-IP/13, December 11,
2009. United States, Aviation Environmental Portfolio Management
Tool for Economics (APMT-Economics) and Its Application in the CAEP/
8 NOX Stringency Analysis, CAEP/8-IP/29, January 6, 2010. A copy of
these documents are in docket number EPA-HQ-OAR-2010-0687.
---------------------------------------------------------------------------

At the time of the CAEP reports, the CAEP/8 NOX standard
for higher thrust engines, i.e., 89.0 kN or more would apply to a total
of 15 engine types. For these types the following technology level
response was anticipated: six types would require no change, one type
would need the first technology level change, five would require the
second technology level, and three would need the third technology
level. For lower thrust engines, i.e., greater that 26.7 but less than
89.0 kN, CAEP listed a total of 13 engine types in their analysis of
the CAEP/8 NOX standard. The following technology level
response was estimated for these types: 11 types would require no
change, 1 type would need the first technology level change, and 1 type
would require a second technology. Based on these analyses, CAEP
concluded that the CAEP/8 NOX standards were technically
feasible within the lead time and time frame identified in the action.
Regarding the costs of this final rule, aircraft turbofan engines
are designed and built for use on aircraft that are sold and operated
throughout the world. As a result, engine manufacturers respond to this
market reality by designing and building engines that conform to ICAO
international standards and practices. This normal business practice
means that engine manufacturers are compelled to make the necessary
business decisions and investments to maximize their international
markets even in the absence of U.S. regulations that would otherwise
codify ICAO standards and practices. Indeed, engine manufacturers have
developed or are already developing improved technology in response to
ICAO standards that match the standards being promulgated in this final
rule. Also, the recommended practices, e.g., test procedures, needed to
demonstrate compliance are being adhered to by manufacturers during
current engine certification tests, or will be even in the absence this
final rule. Therefore, EPA believes that today's standards and
practices that conform with ICAO standards and practices will impose no
real additional burden on engine manufacturers. This finding regarding
no incremental burden, is also consistent with past EPA rulemakings
that adopted ICAO requirements. ((See 62 FR 25356 (May 8, 1997) and 70
FR 69664 (November 11, 2005).
In fact, engine manufacturers have suggested that certain benefits
accrue for compliant products when the U.S. adopts ICAO standards and
practices, but have not provided detailed information regarding these
benefits. Primarily, such action makes FAA certification more
straightforward and transparent. That in turn is advantageous when
marketing their products to potential customers, because compliance
with ICAO standards is an important consideration in purchasing
decisions. It simply removes any question that their engines comply
with international requirements. There will be some cost, however,
associated with our annual reporting requirement for emission related
information. (See section III.D for a description of the reports.)
There are a total of 10 engine manufacturers that would be affected.
Eight of these produce turbofan engines with rated thrusts greater than
26.7 kN, which are already voluntarily reported to the ICAO-related
Emissions Databank (EDB).\107\ We expect the incremental reporting
burden for these manufacturers to be very small because we: (1) Have
significantly reduced the number of reporting elements from those
requested in the EDB, and (2) are adding only three basic reporting
categories to those already requested by the EDB. Also, four of the
eight manufacturers make smaller turbofan and turboprop engines that
will be reporting for the first time. This will add a small incremental
burden for these four manufacturers that otherwise already voluntarily
report to the EDB. There are also two engine manufacturers that only
produce turbofan engines with rated thrusts less than or equal to 26.7
kN and they will be reporting for the first time. For these two
manufacturers we believe that the reporting burden will be small
because all of the information we are requiring should be readily
available, and these manufacturers have a very limited number of engine
models.
---------------------------------------------------------------------------

\107\ As discussed in section III.D, we are requiring a single
report that integrates the new reporting requirement contained in
this final rule with the existing mandatory greenhouse gas (GHG)
reporting of NOX and CO2 as already required
under Sec. 87.64. Combining the existing GHG report with the new
reporting requirement will not increase an engine manufacturer's
reporting burden. A single, integrated report may actually reduce a
manufacturer's total reporting burden somewhat because of the
efficiency inherent in reporting to EPA once instead of twice.
---------------------------------------------------------------------------

We have estimated the annual burden and cost to be about six hours
and $365 per manufacturer. With 10 manufacturers submitting reports,
the total burden of this reporting requirement is estimated to be 60
hours, for a total cost of $3,646.

VII. Consultation With FAA

The requirements contained in this action were developed in
consultation with the Federal Aviation Administration (FAA). Section
231(a)(2)(B)(i) of the CAA requires EPA to ``consult with the
Administrator of the [FAA] on aircraft engine emission standards'' 42
U.S.C. 7571(a)(2)(B)(i), and section 231(a)(2)(B)(ii) indicates that
EPA ``shall not change the aircraft engine emission standards if such
change would significantly increase noise. * * *'' 42 U.S.C.
7571(a)(2)(B)(ii). Section 231(b) of the CAA states that ``[a]ny
regulation prescribed under this section (and any revision thereof)
shall take effect after such period as the Administrator finds
necessary (after consultation with the Secretary of Transportation) to
permit the development and application of the requisite technology,
giving appropriate consideration to the cost of compliance within such
period.'' 42 U.S.C. 7571(b). Section 231(c) provides that any
regulation under section 231 ``shall not apply if disapproved by the
President * * * on the basis of a finding by the Secretary of
Transportation that any such regulation would create a hazard to
aircraft safety.'' 42 U.S.C. 7571(c). Under section 232 of the CAA, the
Department of Transportation (DOT) has the responsibility to enforce
the aircraft emission standards established by EPA

[[Page 36377]]

under section 231.\108\ As in past rulemakings and pursuant to the
above referenced sections of the CAA, EPA has coordinated with the FAA,
i.e., DOT, with respect to today's action.
---------------------------------------------------------------------------

\108\ The functions of the Secretary of Transportation under
part B of title II of the Clean Air Act (Sec. Sec. 231-234, 42
U.S.C. 7571-7574) have been delegated to the Administrator of the
FAA. 49 CFR 1.47(g).
---------------------------------------------------------------------------

Moreover, FAA is the official U.S. delegate to ICAO. FAA agreed to
the amendments at ICAO's Sixth and Eighth Meetings of the Committee on
Aviation Environmental Protection (CAEP/6) after advisement from
EPA.\109\ FAA and EPA were both members of the CAEP's Working Group 3
(among others), whose objective was to evaluate emissions technical
issues and develop recommendations on such issues for CAEP/6 and CAEP/
8. After assessing emissions test procedure amendments and new
NOX standards, Working Group 3 made recommendations to CAEP
on these elements. These recommendations were approved by CAEP/6
meetings prior to their adoption by ICAO in 2004. Similarly, the more
recent Working Group 3 recommendations were approved by CAEP/8 and have
been adopted ICAO.
---------------------------------------------------------------------------

\109\ The Sixth Meeting of CAEP (CAEP/6) occurred in Montreal,
Quebec from February 2 through 12 in 2004.
---------------------------------------------------------------------------

In addition, as discussed above, FAA will have the duty to enforce
today's requirements. As a part of these duties, the FAA witnesses the
emission tests or delegates aspects of that responsibility to the
engine manufacturer, which is then monitored by the FAA.

VIII. Public Participation

We proposed this regulation on July 27, 2011 (76 FR 45012). A
public hearing was held on August 11, 2011 in Chicago, IL. The public
was invited to submit written comments on the proposal during the
formal comment period, which ended on September 26, 2011. We received
eight public comments from aircraft and aircraft engine manufacturers,
airline operators and an individual.
The vast majority of commenters supported the central tenets of the
proposed regulations. That is, there was broad support for the adoption
of these standards and the alignment of U.S. and international
emissions regulations. We received specific comments on several aspects
of the proposal.
Throughout this notice, we discussed the key issues arising from
the public comment and our responses. In addition, we have addressed
all of the public comments in the analysis of comments document
associated with this final action and located in the docket (Docket ID
EPA-HQ-OAR-2010-0687).

IX. Statutory Provisions and Legal Authority

The statutory authority for today's proposal is provided by
sections 114, 231-234 and 301(a) of the Clean Air Act, as amended, 42
U.S.C. Sec. Sec. 7414, 7571-7574 and 7601(a). See section II of
today's rule for discussion of how EPA meets the CAA's statutory
requirements.

X. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review, and Executive
Order 13563: Improving Regulation and Regulatory Review

Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993),
this action is a ``significant regulatory action.'' This action
promulgates new aircraft engine emissions regulations and as such,
requires consultation and coordination with the Federal Aviation
Administration (FAA). OMB has determined that this action raises ``* *
* novel legal or policy issues arising out of legal mandates, the
President's priorities, or the principles set forth in the EO.''
Accordingly, EPA submitted this action to the Office of Management and
Budget (OMB) for review under EO 12866 and 13563 (76 FR 3821, January
21, 2011) and any changes made in response to OMB recommendations have
been documented in the docket for this action.
As discussed further in section V, we do not attribute any costs to
the compliance with today's regulations that conform to ICAO standards
and recommended practices. Aircraft turbofan engines are international
commodities. As a result, engine manufacturers respond to this market
reality by designing and building engines that conform to ICAO
international standards and practices. Therefore, engine manufacturers
are compelled to make the necessary business decisions and investments
to maximize their international markets even in the absence of U.S.
action. Indeed, engine manufacturers have or are already responding, or
will in the future, to ICAO requirements that match the standards and
practices adopted here. Therefore, EPA believes that today's
requirements that conform with ICAO standards and practices will impose
no real additional burden on engine manufacturers. This finding is also
consistent with past EPA rulemakings that adopted ICAO requirements.
There is, nonetheless, a small burden associated with the reporting
requirements, as discussed in section IX.B.

B. Paperwork Reduction Act

The information collection requirements in this rule have been
submitted for approval to the Office of Management and Budget (OMB)
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The
information collection requirements are not enforceable until OMB
approves them.
Manufacturers keep substantial records to document their compliance
with emission standards. We need to be able to access this data to
conduct accurate emission inventories, understand how emission
standards affect the current fleet, and develop appropriate policy in
the form of future emission standards. Most manufacturers are already
accustomed to reporting much of this information to ICAO. However,
these reports are voluntary and aperiodic. As part of this action, we
are requiring that engine manufacturers send this information to EPA on
an annual basis. We are also requiring manufacturers to send us their
annual production volumes, which we would treat as confidential
business information. Under the Clean Air Act, we are authorized to
require manufacturers to establish and maintain necessary records, make
reports, and provide such other information as we may reasonably
require to execute our functions under the Act. See 42 U.S.C.
7414(a)(1). We will simply require manufacturers to add the required
information items to the annual report they are already required to
submit with information about NOX and CO2
emission levels. See section III.D for a more complete description of
the annual reporting requirement.
We have estimated the total annual burden of the reporting
requirement to be 60 hours, and the total cost to be $3,646. The annual
burden and cost per respondent is estimated to be 6 hours and $365.
Burden is defined at 5 CFR 1320.3(b).
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9. When this ICR is
approved by OMB, the Agency will publish a technical amendment to 40
CFR part 9 in the Federal Register to display the OMB control number
for the approved

[[Page 36378]]

information collection requirements contained in this final rule.

C. Regulatory Flexibility Analysis

The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
For purposes of assessing the impacts of today's rule on small
entities, small entity is defined as: (1) A small business as defined
by SBA size standards; (2) a small governmental jurisdiction that is a
government of a city, county, town, school district or special district
with a population of less than 50,000; and (3) a small organization
that is any not-for-profit enterprise which is independently owned and
operated and is not dominant in its field. The following Table 4
provides an overview of the primary SBA small business categories
potentially affected by this regulation.

Table 4--Primary Potentially Affected SBA Small Business Categories
----------------------------------------------------------------------------------------------------------------
Industry NAICS a Codes Defined by SBA as a small business if: b
----------------------------------------------------------------------------------------------------------------
Manufacturers of new aircraft engines.......... 336412 <1,000 employees.
Manufacturers of new aircraft.................. 336411 <1,500 employees.
----------------------------------------------------------------------------------------------------------------
a North American Industry Classification System (NAICS).
b According to SBA's regulations (13 CFR part 121), businesses with no more than the listed number of employees
or dollars in annual receipts are considered ``small entities'' for purposes of a regulatory flexibility
analysis.

After considering the economic impacts of today's rule on small
entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities. Small
governmental jurisdictions and small organizations as described above
will not be impacted. We have determined that the estimated effect of
the rule's reporting requirement is to affect one small entity turbofan
engine manufacturer with costs less than one percent of revenues. This
one company represents all of the small businesses affected by the
regulations. An analysis of the impacts of the proposed rule on small
businesses has been prepared and placed in the docket for this
rulemaking.\110\ Since this final rule is largely unchanged from the
proposal, that analysis remains valid for the final rule.
---------------------------------------------------------------------------

\110\ ``Small Business Impact Memo, Proposed Aircraft Engine
Emission Standards--Determination of No SISNOSE,'' EPA memo from
Solveig Irvine to Alexander Cristofaro, November, 2010.
---------------------------------------------------------------------------

D. Unfunded Mandates Reform Act

This rule does not contain a Federal mandate that may result in
expenditures of $100 million or more for State, local, and tribal
governments, in the aggregate, or the private sector in any one year.
As discussed in section III, today's action will establish consistency
between U.S. and existing international emission standards. The engine
manufacturers are already developing the technology to meet the
existing ICAO standards, and we do not believe it is appropriate to
attribute the costs of that technology to this action. Thus, this rule
is not subject to the requirements of sections 202 or 205 of UMRA.
This rule is also not subject to the requirements of section 203 of
UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments. The provisions of
this rule apply to the manufacturers of aircraft and aircraft engines,
and as such would not affect small governments.

E. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government, as
specified in Executive Order 13132. As discussed earlier, section 233
of the CAA preempts states from adopting or enforcing aircraft engine
emission standards that are not identical to our standards. This rule
revises the Code of Federal Regulations to more accurately reflect the
statutory preemption established by the Clean Air Act. This rule does
not impose any new preemption of State and local law. Thus, Executive
Order 13132 does not apply to this action.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

These rules regulate aircraft manufacturers and aircraft engine
manufacturers. We do not believe that Tribes own any of these
businesses nor are there other implications for Tribes. Thus, Executive
Order 13175 does not apply to this action.

G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks

This rule is not subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it is not economically significant as defined
in EO 12866 and the Agency does not believe the environmental health
risks or safety risks addressed by this action present a
disproportionate risk to children. See section II.B.2 for a discussion
of the health impacts of NOX emissions.

H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use

This action is not a ``significant energy action'' as defined in
Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not
likely to have a significant adverse effect on the supply,
distribution, or use of energy. These aircraft engine emissions
regulations are not expected to result in any changes to aircraft fuel
consumption.

I. National Technology Transfer Advancement Act

Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113 (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. NTTAA directs EPA to provide

[[Page 36379]]

Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards.
This rulemaking involves technical standards for testing emissions
for aircraft gas turbine engines. EPA is using test procedures
contained in ICAO's International Standards and Recommended Practices
Environmental Protection, Annex 16, Volume II along with the
modifications contained in this rulemaking.\111\ These procedures are
currently used by all manufacturers of aircraft gas turbine engines
(with thrust greater than 26.7 kN) to demonstrate compliance with ICAO
emissions standards.
---------------------------------------------------------------------------

\111\ ICAO International Standards and Recommended Practices
Environmental Protection, Annex 16, Volume II, ``Aircraft Engine
Emissions,'' Second Edition, July 1993--Amendment 3, March 20, 1997.
Copies of this document can be obtained from ICAO (www.icao.int).
---------------------------------------------------------------------------

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes
federal executive policy on environmental justice. Its main provision
directs federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
EPA has determined that this rule will not have disproportionately
high and adverse human health or environmental effects on minority or
low-income populations because it increases the level of environmental
protection for all affected populations without having any
disproportionately high and adverse human health or environmental
effects on any population, including any minority or low-income
population.

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective July 18, 2012.

L. Executive Order 13609: Promoting International Regulatory
Cooperation

Executive Order (EO) 13609 (77 FR 26413, May 4, 2012) promotes
international regulatory cooperation in order to identify approaches
that are at least as protective as those that are or would be adopted
in the absence of such cooperation in meeting shared challenges
involving health, safety, labor, security, environmental, and other
issues. International regulatory cooperation can also reduce,
eliminate, or prevent unnecessary differences in regulatory
requirements.
These final standards are identical to the international standards
developed through EPA's active participation in the United Nation's
International Civil Aviation Organization (ICAO) activities. EPA has
historically been a principal participant in the development of U.S.
policy in various ICAO working groups and other international venues,
assisting and advising the Federal Aviation Administration on aviation
emissions, technology, and policy matters. These provisions provide a
means by which the United States can meet its obligations under the
Chicago Convention and ensure that engine manufacturers maintain
worldwide acceptability of their products.

List of Subjects

40 CFR Part 87

Environmental protection, Air pollution control, Aircraft,
Incorporation by reference.

40 CFR Part 1068

Environmental protection, Administrative practice and procedure,
Confidential business information, Imports, Motor vehicle pollution,
Penalties, Reporting and recordkeeping requirements, Warranties.

Dated: June 1, 2012.
Lisa P. Jackson,
Administrator.

For the reasons described in the preamble, title 40, chapter I, of
the Code of Federal Regulations is amended as set forth below.

PART 87--CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT
ENGINES

0
1. The authority citation for part 87 is revised to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart A--[Amended]

0
2. Revise Sec. 87.1 to read as follows:

Sec. 87.1 Definitions.

The definitions in this section apply to this part. The definitions
apply to all subparts. Any terms not defined in this section have the
meaning given in the Clean Air Act. The definitions follow:
Act means the Clean Air Act, as amended (42 U.S.C. 7401 et seq).
Administrator means the Administrator of the Environmental
Protection Agency and any other officer or employee of the
Environmental Protection Agency to whom authority involved may be
delegated.
Aircraft has the meaning given in 14 CFR 1.1, which defines
aircraft to mean a device used or intended to be used for flight in the
air. Note that under Sec. 87.3, the requirements of this part
generally apply only to propulsion engines used on certain airplanes
for which U.S. airworthiness certificates are required.
Aircraft engine means a propulsion engine which is installed in or
which is manufactured for installation in an aircraft.
Aircraft gas turbine engine means a turboprop, turbofan, or
turbojet aircraft engine.
Characteristic level has the meaning given in Appendix 6 of ICAO
Annex 16 (as of July 2008). The characteristic level is a calculated
emission level for each pollutant based on a statistical assessment of
measured emissions from multiple tests.
Class TP means all aircraft turboprop engines.
Class TF means all turbofan or turbojet aircraft engines or
aircraft engines designed for applications that otherwise would have
been fulfilled by turbojet and turbofan engines except engines of class
T3, T8, and TSS.
Class T3 means all aircraft gas turbine engines of the JT3D model
family.
Class T8 means all aircraft gas turbine engines of the JT8D model
family.
Class TSS means all aircraft gas turbine engines employed for
propulsion of aircraft designed to operate at supersonic flight speeds.
Commercial aircraft engine means any aircraft engine used or
intended for use by an ``air carrier,'' (including those engaged in
``intrastate air transportation'') or a ``commercial

[[Page 36380]]

operator'' (including those engaged in ``intrastate air
transportation'') as these terms are defined in subtitle 7 of title 49
of the United States Code and title 14 of the Code of Federal
Regulations.
Commercial aircraft gas turbine engine means a turboprop, turbofan,
or turbojet commercial aircraft engine.
Date of introduction or introduction date means the date of
manufacture of the first individual production engine of a given engine
model or engine type certificate family to be certificated. This does
not include test engines or other engines not placed into service.
Date of manufacture means the date on which a manufacturer is
issued documentation by FAA (or other competent authority for engines
certificated outside the United States) attesting that the given engine
conforms to all applicable requirements. This date may not be earlier
that the date on which assembly of the engine is complete. Where the
manufacturer does not obtain such documentation from FAA (or other
competent authority for engines certificated outside the United
States), date of manufacture means the date of final assembly of the
engine.
Derivative engine for emissions certification purposes means an
engine that has the same or similar emissions characteristics as an
engine covered by a U.S. type certificate issued under 14 CFR part 33.
These characteristics are specified in Sec. 87.48.
Designated EPA Program Officer means the Director of the Assessment
and Standards Division, 2000 Traverwood Drive, Ann Arbor, Michigan
48105.
DOT Secretary means the Secretary of the Transportation and any
other officer or employee of the Department of Transportation to whom
the authority involved may be delegated.
Engine means an individual engine. A group of identical engines
together make up an engine model or sub-model.
Engine model means an engine manufacturer's designation for an
engine grouping of engines and/or engine sub-models within a single
engine type certificate family, where such engines have similar design,
including being similar with respect to the core engine and combustor
designs.
Engine sub-model means a designation for a grouping of engines with
essentially identical design, especially with respect to the core
engine and combustor designs and other emission-related features.
Engines from an engine sub-model must be contained within a single
engine model. For purposes of this part, an original engine model
configuration is considered a sub-model. For example, if a manufacturer
initially produces an engine model designated ABC and later introduces
a new sub-model ABC-1, the engine model consists of two sub-models: ABC
and ABC-1.
Engine type certificate family means a group of engines (comprising
one or more engine models, including sub-models and derivative engines
for emissions certification purposes of those engine models) determined
by FAA to have a sufficiently common design to be grouped together
under a type certificate.
EPA means the U.S. Environmental Protection Agency.
Except means to routinely allow engines to be produced and sold
that do not meet (or do not fully meet) otherwise applicable standards.
(Note that this definition applies only with respect to spare engines
and that the term ``except'' has its plain meaning in other contexts.)
Excepted engines must conform to regulatory conditions specified for an
exception in this part and other applicable regulations. Excepted
engines are deemed to be ``subject to'' the standards of this part even
though they are not required to comply with the otherwise applicable
requirements. Engines excepted with respect to certain standards must
comply with other standards from which they are not excepted.
Exempt means to allow (through a formal case-by-case process)
engines to be produced and sold that do not meet (or do not fully meet)
otherwise applicable standards. Exempted engines must conform to
regulatory conditions specified for an exemption in this part and other
applicable regulations. Exempted engines are deemed to be ``subject
to'' the standards of this part even though they are not required to
comply with the otherwise applicable requirements. Engines exempted
with respect to certain standards must comply with other standards as a
condition of the exemption.
Exhaust emissions means substances emitted to the atmosphere from
exhaust discharge nozzles, as measured by the test procedures specified
in subpart G of this part.
FAA means the U.S. Department of Transportation, Federal Aviation
Administration.
Fuel venting emissions means raw fuel, exclusive of hydrocarbons in
the exhaust emissions, discharged from aircraft gas turbine engines
during all normal ground and flight operations.
Good engineering judgment involves making decisions consistent with
generally accepted scientific and engineering principles and all
relevant information, subject to the provisions of 40 CFR 1068.5.
ICAO Annex 16 means Volume II of Annex 16 to the Convention on
International Civil Aviation (incorporated by reference in Sec. 87.8).
In-use aircraft gas turbine engine means an aircraft gas turbine
engine which is in service.
Military aircraft means aircraft owned by, operated by, or produced
for sale to the armed forces or other agency of the federal government
responsible for national security (including but not limited to the
Department of Defense) and other aircraft considered to be military
aircraft under international law and conventions.
New means relating to an aircraft or aircraft engine that has never
been placed into service.
Operator means any person or company that owns or operates an
aircraft.
Production cutoff date or date of the production cutoff means the
date on which interim phase-out allowances end.
Rated output (rO) means the maximum power/thrust available for
takeoff at standard day conditions as approved for the engine by FAA,
including reheat contribution where applicable, but excluding any
contribution due to water injection, expressed in kilowatts or
kilonewtons (as applicable) and rounded to at least three significant
figures.
Rated pressure ratio (rPR) means the ratio between the combustor
inlet pressure and the engine inlet pressure achieved by an engine
operating at rated output, rounded to at least three significant
figures.
Round has the meaning given in 40 CFR 1065.1001.
Smoke means the matter in exhaust emissions that obscures the
transmission of light, as measured by the test procedures specified in
subpart G of this part.
Smoke number means a dimensionless value quantifying smoke
emissions calculated in accordance with ICAO Annex 16.
Spare engine means an engine installed (or intended to be
installed) on an in-service aircraft to replace an existing engine and
that is excepted as described in Sec. 87.50(c).
Standard day conditions means the following ambient conditions:
temperature = 15 [deg]C, specific humidity = 0.00634 kg H2O/
kg dry air, and pressure = 101.325 kPa.
Subsonic means relating to aircraft that are not supersonic
aircraft.

[[Page 36381]]

Supersonic means relating to aircraft that are certificated to fly
faster than the speed of sound.
Tier 0 means relating to an engine that is subject to the Tier 0
NOX standards specified in Sec. 87.21.
Tier 2 means relating to an engine that is subject to the Tier 2
NOX standards specified in Sec. 87.21.
Tier 4 means relating to an engine that is subject to the Tier 4
NOX standards specified in Sec. 87.21.
Tier 6 means relating to an engine that is subject to the Tier 6
NOX standards specified in Sec. 87.23.
Tier 8 means relating to an engine that is subject to the Tier 8
NOX standards specified in Sec. 87.23.
Turbofan engine means a gas turbine engine designed to create its
propulsion from exhaust gases and from air that bypasses the combustion
process and is accelerated in a ducted space between the inner (core)
engine case and the outer engine fan casing.
Turbojet engine means a gas turbine engine that is designed to
create all of its propulsion from exhaust gases.
Turboprop engine means a gas turbine engine that is designed to
create most of its propulsion from a propeller driven by a turbine,
usually through a gearbox.
Turboshaft engine means a gas turbine engine that is designed to
drive a rotor transmission system or a gas turbine engine not used for
propulsion.
U.S.-registered aircraft means an aircraft that is on the U.S.
Registry.
We (us, our) means the Administrator of the Environmental
Protection Agency and any authorized representatives.

0
3. Revise Sec. 87.2 to read as follows:

Sec. 87.2 Abbreviations.

The abbreviations used in this part have the following meanings:

% percent
[deg] degree
CO carbon monoxide
CO2 carbon dioxide
g gram
HC hydrocarbon(s)
kN kilonewton
kW kilowatt
LTO landing and takeoff
NOX oxides of nitrogen
rO rated output
rPR rated pressure ratio
SN smoke number

0
4. Revise Sec. 87.3 to read as follows:

Sec. 87.3 General applicability and requirements.

(a) The regulations of this part apply to engines on all aircraft
that are required to be certificated by FAA under 14 CFR part 33 except
as specified in this paragraph (a). These regulations do not apply to
the following aircraft engines:
(1) Reciprocating engines (including engines used in ultralight
aircraft).
(2) Turboshaft engines such as those used in helicopters.
(3) Engines used only in aircraft that are not airplanes. For
purposes of this paragraph (a)(3), ``airplane'' means a fixed-wing
aircraft that is heavier than air.
(4) Engines not used for propulsion.
(b) Under section 232 of the Act, the Secretary of Transportation
issues regulations to ensure compliance with the standards and related
requirements of this part (42 U.S.C. 7572).
(c) The Secretary of Transportation shall apply these regulations
to aircraft of foreign registry in a manner consistent with obligations
assumed by the United States in any treaty, convention or agreement
between the United States and any foreign country or foreign countries.
(d) No State or political subdivision of a State may adopt or
attempt to enforce any aircraft or aircraft engine standard respecting
emissions unless the standard is identical to a standard applicable to
such aircraft under this part (including prior-tier standards
applicable to exempt engines).

Sec. 87.5 [Removed]

0
5. Remove Sec. 87.5.

0
6. Revise Sec. 87.6 to read as follows:

Sec. 87.6 Aircraft safety.

The provisions of this part will be revised if at any time the DOT
Secretary determines that an emission standard cannot be met within the
specified time without creating a hazard to aircraft safety.

Sec. 87.7 [Removed]

0
7. Remove Sec. 87.7.

0
8. Revise Sec. 87.8 to read as follows:

Sec. 87.8 Incorporation by reference.

(a) Certain material is incorporated by reference into this part
with the approval of the Director of the Federal Register under 5
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that
specified in this section, the Environmental Protection Agency must
publish notice of change in the Federal Register and the material must
be available to the public. All approved material is available for
inspection at U.S. EPA, Air and Radiation Docket and Information
Center, 1301 Constitution Ave. NW., Room B102, EPA West Building,
Washington, DC 20460, (202) 202-1744, and is available from the sources
listed below. It is also available for inspection at the National
Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call 202-741-6030 or go to
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
(b) International Civil Aviation Organization, Document Sales Unit,
999 University Street, Montreal, Quebec, Canada H3C 5H7, (514) 954-
8022, www.icao.int, or sales@icao.int.
(1) Annex 16 to the Convention on International Civil Aviation,
Environmental Protection, Volume II--Aircraft Engine Emissions, Third
Edition, July 2008 (ICAO Annex 16). IBR approved for Sec. Sec. 87.1,
87.42(c), and 87.60(a) and (b).
(2) [Reserved]

Subpart C--[Amended]

0
9. Amend Sec. 87.21 as follows:
0
a. By revising the section heading.
0
b. By adding introductory text.
0
c. By revising paragraphs (d)(1)(iii), (d)(1)(iv), (d)(1)(vi)
introductory text, (e)(1), and (f).

Sec. 87.21 Exhaust emission standards for Tier 4 and earlier engines.

This section describes the emission standards that apply for Tier 4
and earlier engines that apply for aircraft engines manufactured before
July 18, 2012 and certain engines exempted under Sec. 87.50. Note that
the tier of standards identified for an engine relates to
NOX emissions and that the specified standards for HC, CO,
and smoke emissions apply independent of the changes to the
NOX emission standards.
(d) * * *
(1) * * *
(iii) The following Tier 0 emission standard applies for engines of
a type or model of which the date of manufacture of the first
individual production model was on or before December 31, 1995 and for
which the date of manufacture of the individual engine was on or before
December 31, 1999.

Oxides of Nitrogen: (40 + 2(rPR)) grams/kilonewton rO.

(iv) The following Tier 2 emission standard applies for engines of
a type or model of which the date of manufacture of the first
individual production model was after December 31, 1995 or for which
the date of manufacture of the individual engine was after December 31,
1999:

Oxides of Nitrogen: (32 + 1.6(rPR)) grams/kilonewton rO.
* * * * *

[[Page 36382]]

(vi) The following Tier 4 emission standards apply for engines of a
type or model of which the date of manufacture of the first individual
production model was after December 31, 2003:
* * * * *
(e) * * *
(1) Class TF of rated output less than 26.7 kilonewtons
manufactured on or after August 9, 1985:

SN = 83.6(rO)^-\0.274\ (rO is in kilonewtons) not to exceed a
maximum of SN = 50.
* * * * *
(f) The standards in this section refer to a composite emission
sample measured and calculated in accordance with the procedures
described in subpart G of this part.

0
10. Add a new Sec. 87.23 to subpart C to read as follows:

Sec. 87.23 Exhaust emission standards for Tier 6 and Tier 8 engines.

This section describes the emission standards that apply for Tier 6
and Tier 8 engines. The standards of this section apply for aircraft
engines manufactured on or after July 18, 2012, except where we specify
that they apply differently by year, or where the engine is exempt from
one or more standards of this section. Except as specified in paragraph
(d) of this section, these standards apply based on the date the engine
is manufactured. Where a gaseous emission standard is specified by a
formula, calculate and round the standard to three significant figures
or to the nearest 0.1 g/kN (for standards at or above 100 g/kN). Where
a smoke standard is specified by a formula, calculate and round the
standard to the nearest 0.1 SN. Engines comply with an applicable
standard if the testing results show that the engine type certificate
family's characteristic level does not exceed the numerical level of
that standard, as described in Sec. 87.60. The tier of standards
identified for an engine relates to NOX emissions and that
the specified standards for HC, CO, and smoke emissions apply
independent of the changes to the NOX emission standards.
(a) New turboprop aircraft engines with rated output at or above
1,000 kilowatts must comply with a smoke standard of 187 [middot]
rO^-0.168.
(b) New supersonic engines must comply with the standards shown in
the following table:

Table 1 to Sec. 87.23--Smoke and Gaseous Emission Standards for New Supersonic Engines
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rated output Smoke number HC (g/kN rated output) NOX (g/kN rated output) CO (g/kN rated output)
--------------------------------------------------------------------------------------------------------------------------------------------------------
rO < 26.7 kN.................... ........................ 140 [middot] 0.92rPR 36 + 2.42 [middot] rPR 4550 [middot] rPR-1.03
rO [gteqt] 26.7 kN.............. 83.6 [middot] rO-0.274 140 [middot] 0.92rPR 36+2.42 [middot] rPR 4550 [middot] rPR-1.03
or 50.0, whichever is
smaller.
--------------------------------------------------------------------------------------------------------------------------------------------------------

(c) New turbofan or turbojet aircraft engines that are installed in
subsonic aircraft must comply with the following standards:
(1) The applicable smoke, HC, and CO standards are shown in the
following table:

Table 2 to Sec. 87.23--Smoke, HC, and CO Standards for New Subsonic Turbofan or Turbojet Engines
----------------------------------------------------------------------------------------------------------------
Gaseous emission standards (g/kN
rated output)
Rated output (kN) Smoke standard -----------------------------------
HC CO
----------------------------------------------------------------------------------------------------------------
rO < 26.7 kN............................. 83.6 [middot] rO-0.274 or 50.0, ................ ................
whichever is smaller.
rO >= 26.7 kN............................ 83.6 [middot] rO-0.274 or 50.0, 19.6 118
whichever is smaller.
----------------------------------------------------------------------------------------------------------------

(2) The Tier 6 NOX standards apply as described in this
paragraph (c)(2). See paragraph (d) of this section for provisions
related to models introduced before these standards started to apply
and engines determined to be derivative engines for emissions
certification purposes under the requirements of this part.

Table 3 to Sec. 87.23--Tier 6 NOX Standards for New Subsonic Turbofan or Turbojet Engines With Rated Output Above 26.7 kN
--------------------------------------------------------------------------------------------------------------------------------------------------------
and the rated output (in kN)
If the rated pressure ratio is . . . is . . . The NOX emission standard (in g/kN rated output) is . . .
--------------------------------------------------------------------------------------------------------------------------------------------------------
rPR <= 30................................ 26.7 < rO <= 89............. 38.5486 + 1.6823 [middot] PR-0.2453 [middot] rO-0.00308 [middot] rPR [middot]
rO
rO > 89..................... 16.72 + 1.4080 [middot] rPR
30 < rPR < 82.6.......................... 26.7 < rO <= 89............. 46.1600 + 1.4286 [middot] rPR - 0.5303 [middot] rO + 0.00642 [middot] rPR
[middot] rO
rO > 89..................... -1.04 + 2.0 [middot] rPR
rPR >= 82.6.............................. all......................... 32 + 1.6 [middot] rPR
--------------------------------------------------------------------------------------------------------------------------------------------------------

(3) The Tier 8 NOX standards apply as described in this
paragraph (c)(3) beginning January 1, 2014. See paragraph (d) of this
section for provisions related to models introduced before January 1,
2014 apply and engines determined to be derivative engines for
emissions certification purposes under the requirements of this part.

[[Page 36383]]

Table 4 to Sec. 87.23--Tier 8 NOX Standards for New Subsonic Turbofan
or Turbojet Engines With Rated Output Above 26.7 kN
------------------------------------------------------------------------
The NOX emission
If the rated pressure ratio and the rated output standard (in g/kN
is . . . (in kN) is . . . rated output) is . .
.
------------------------------------------------------------------------
rPR <= 30................... 26.7 < rO <= 89..... 40.052 + 1.5681
[middot] rPR -
0.3615 [middot] rO
0.0018 [middot]
rPR [middot] rO
rO > 89............. 7.88 + 1.4080
[middot] rPR
30 < rPR < 104.7............ 26.7 < rO <= 89..... 41.9435 + 1.505 rPR-
0.5823 [middot] rO
+ 0.005562-rPR
[middot] rO
rO > 89............. -9.88 + 2.0 [middot]
rPR
rPR >= 104.7................ all................. 32 + 1.6 [middot]
rPR
------------------------------------------------------------------------

(d) This paragraph (d) specifies phase-in provisions that allow
continued production of certain engines after the Tier 6 and Tier 8
standards begin to apply.
(1) Engine type certificate families certificated with
characteristic levels at or below the Tier 4 NOX standards
of Sec. 87.21 (as applicable based on rated output and rated pressure
ratio) and introduced before July 18, 2012 may be produced through
December 31, 2012 without meeting the Tier 6 NOX standards
of paragraph (c)(2) of this section. This also applies for engines that
are covered by the same type certificate and are determined to be
derivative engines for emissions certification purposes under the
requirements of this part. Note that after this production cutoff date
for the Tier 6 NOX standards, such engines may be produced
only if they are covered by an exemption under Sec. 87.50. This
production cutoff does not apply to engines installed (or delivered for
installation) on military aircraft.
(2) Engine type certificate families certificated with
characteristic levels at or below the Tier 6 NOX standards
of paragraph (c)(2) of this section with an introduction date before
January 1, 2014 may continue to be produced. This also applies for
engines that are covered by the same type certificate and are
determined to be derivative engines for emissions certification
purposes under the requirements of this part.
(3) An engine manufacturer may produce up to six newly manufactured
Tier 4 engines on or after July 18, 2012, subject to the provisions of
this paragraph (d)(3). Tier 4 engines meeting the criteria of this
paragraph (d)(3) are excepted without request from the otherwise
applicable Tier 6 NOX emission standard. To be eligible for
this exception the engines must have a date of manufacture prior to
August 31, 2013 and be fully compliant with all requirements applicable
to Tier 4 engines. The manufacturer must include these engines in the
report required by Sec. 87.50. This exception is void for any
manufacturer that produces more than six excepted engines under this
paragraph.

0
11. Add a new subpart E containing Sec. Sec. 87.40, 87.42, 87.46, and
87.48 to read as follows:
Subpart E--Certification Provisions
Sec.
87.40 General certification requirement.
87.42 Production report to EPA.
87.46 Recordkeeping.
87.48 Derivative engines for emissions certification purposes.

Subpart E--Certification Provisions

Sec. 87.40 General certification requirement.

Manufacturers of engines subject to this part must meet the
requirements of title 14 of the Code of Federal Regulations as
applicable.

Sec. 87.42 Production report to EPA.

Engine manufacturers must submit an annual production report as
specified in this section. This requirement applies for engines
produced on or after January 1, 2013.
(a) You must submit the report for each calendar year in which you
produce any engines subject to emission standards under this part. The
report is due by February 28 of the following calendar year. Note that
Sec. 87.64 requires you to report CO2 emission rates to EPA
in addition to NOX. Include these data in the report
required by this section. If you produce exempted or excepted engines,
you may submit a single report with information on exempted/excepted
and normally certificated engines.
(b) Send the report to the Designated EPA Program Officer.
(c) In the report, specify your corporate name and the year for
which you are reporting. Include information as described in this
section for each engine sub-model subject to emission standards under
this part. List each engine sub-model produced or certificated during
the calendar year, including the following information for each sub-
model:
(1) The type of engine (turbofan, turboprop, etc.) and complete
sub-model name, including any applicable model name, sub-model
identifier, and engine type certificate family identifier.
(2) The certificate under which it was produced. Identify all the
following:
(i) The type certificate number. Specify if the sub-model also has
a type certificate issued by a certificating authority other than FAA.
(ii) Your corporate name as listed in the certificate.
(iii) Emission standards to which the engine is certificated.
(iv) Date of issue of type certificate (month and year).
(v) Whether or not this is a derivative engine for emissions
certification purposes. If so, identify the original certificated
engine model.
(vi) The engine sub-model that received the original type
certificate for an engine type certificate family.
(3) Identify the combustor of the sub-model, where more than one
type of combustor is available.
(4) The calendar-year production volume of engines from the sub-
model that are covered by an FAA type certificate. Record zero for sub-
models with no engines produced during the calendar year, or state that
the engine model is no longer in production and list the date of
manufacture (month and year) of the last engine produced. Specify the
number of these engines that are intended for use on new aircraft and
the number that are intended for use as non-exempt engines on in-use
aircraft. For engines delivered without a final sub-model status and
for which the manufacturer has not ascertained the engine's sub-model
when installed before submitting its production report, the
manufacturer may do any of the following in its initial report, and
amend it later:
(i) List the sub-model that was shipped or the most probable sub-
model.
(ii) List all potential sub-models.
(iii) State ``Unknown Sub-Model.''
(5) The number of engines tested and the number of test runs for
the applicable type certificate.

[[Page 36384]]

(6) The applicable test data and related information specified in
Part III, Section 2.4 of ICAO Annex 16 (incorporated by reference in
Sec. 87.8), except as otherwise allowed by this paragraph. For
purposes of this paragraph (c)(6), applicable test data means data
required to certify the engine sub-model, which would typically include
NOX, HC, CO and smoke number. However, applicable test data
would not include NOX, HC, or CO emissions for engines
subject to only smoke standards. Note that Sec. 87.64 also requires
you to report CO2 emissions. Specify thrust in kW for
turboprop engines. You may omit the following items specified in Part
III, Section 2.4 of ICAO Annex 16:
(i) Fuel specifications including fuel specification reference and
hydrogen/carbon ratio.
(ii) Methods used for data acquisition, correcting for ambient
conditions, and data analysis.
(iii) Intermediate emission indices and rates, however you may not
omit the final characteristic level for each regulated pollutant in
units of g/kN or g/kW.
(d) Clearly show what information you consider confidential by
marking, circling, bracketing, stamping, or some other method. We will
store your confidential information as described in 40 CFR part 2.
Also, we will disclose it only as specified in 40 CFR part 2. If you
send us information without claiming it is confidential, we may make it
available to the public without further notice to you, as described in
40 CFR 2.204.
(e) Include the following signed statement and endorsement by an
authorized representative of your company: ``We submit this report
under 40 CFR 87.42. All the information in this report is true and
accurate to the best of my knowledge.''
(f) Where information provided for the previous year remains valid
and complete, you may report your production volumes and state that
there are no changes, without resubmitting the other information
specified in this section.

Sec. 87.46 Recordkeeping.

(a) You must keep a copy of any reports or other information you
submit to us for at least three years.
(b) Store these records in any format and on any media, as long as
you can promptly send us organized, written records in English if we
ask for them. You must keep these records readily available. We may
review them at any time.

Sec. 87.48 Derivative engines for emissions certification purposes.

(a) General. A type certificate holder may request from the FAA a
determination that an engine configuration is considered a derivative
engine for emissions certification purposes. This would mean that the
engine configuration is determined to be similar in design to a
previously certificated engine (the ``original'' engine) for purposes
of compliance with exhaust emission standards (gaseous and smoke). In
order for the engine configuration to be considered a derivative engine
for emission purposes under this part, it must have been derived from
an original engine that was certificated to the requirements of 14 CFR
part 33, and one of the following conditions must be met:
(1) The FAA determined that a safety issue exists that requires an
engine modification.
(2) Emissions from the derivative engines are determined to be
similar. In general, this means the emissions must meet the criteria
specified in paragraph (b) of this section. FAA may adjust these
criteria in unusual circumstances, consistent with good engineering
judgment.
(3) All of the regulated emissions from the derivative engine are
lower than the original engine.
(b) Emissions similarity. (1) The type certificate holder must
demonstrate that the proposed derivative engine model's emissions meet
the applicable standards and differ from the original model's emission
rates only within the following ranges:
(i) 3.0 g/kN for NOX.
(ii) 1.0 g/kN for HC.
(iii) 5.0 g/kN for CO.
(iv) 2.0 SN for smoke.
(2) If the characteristic level of the original certificated engine
model (or any other sub-models within the emission type certificate
family tested for certification) before modification is at or above 95%
of the applicable standard for any pollutant, you must measure the
proposed derivative engine model's emissions for all pollutants to
demonstrate that the derivative engine's resulting characteristic
levels will not exceed the applicable emission standards. If the
characteristic levels of the originally certificated engine model (and
all other sub-models within the emission type certificate family tested
for certification) are below 95% of the applicable standard for each
pollutant, then, you may use engineering analysis to demonstrate that
the derivative engine will not exceed the applicable emission
standards, consistent with good engineering judgment. The engineering
analysis must address all modifications from the original engine,
including those approved for previous derivative engines.
(c) Continued production allowance. Where we allow continued
production of an engine model after new standards begin to apply, you
may also produce engine derivatives if they conform to the
specifications of this section.
(d) Non-derivative engines. If the FAA determines that an engine
model does not meet the requirements for a derivative engine for
emissions certification purposes, the type certificate holder is
required to demonstrate that the engine complies with the emissions
standards applicable to a new engine type.

0
12. Add a new subpart F containing Sec. 87.50 to read as follows:

Subpart F--Exemptions and Exceptions

Sec. 87.50 Exemptions and exceptions.

This section specifies provisions related to exempting/excepting
engines from some or all of the standards and requirements of this part
87. Exempted/excepted engines must conform to regulatory conditions
specified for an exemption in this section and other applicable
regulations. Exempted/excepted engines are deemed to be ``subject to''
the standards of this part even though they are not required to comply
with the otherwise applicable requirements. Engines exempted/excepted
with respect to certain standards must comply with other standards.
Exemption requests under paragraph (a) of this section must be approved
by the FAA, with the written concurrence of EPA, to be effective.
Exemption requests under paragraph (b) of this section must be approved
only by the FAA to be effective. Exceptions do not require a case-by-
case FAA approval.
(a) Engines installed in new aircraft. Type certificate holders may
request an exemption to produce a limited number of newly manufactured
engines through December 31, 2016, to be installed in new aircraft as
specified in this paragraph (a). This exemption is limited to
NOX emissions from engines that are covered by a valid type
certificate issued by FAA.
(1) Submit your request for an exemption to the FAA before
producing the engines to be exempted, who will provide a copy to the
Designated EPA Program Officer. Exemption by an authority outside the
United States does not satisfy this requirement. Unless EPA and FAA
allow otherwise, all requests must include the following:

[[Page 36385]]

(i) Your corporate name and an authorized representative's contact
information.
(ii) A description of the engines for which you are requesting the
exemption including the type certificate number and date it was issued
by the FAA. Include in your description the engine model and sub-model
names and the types of aircraft in which the engines are expected to be
installed. Specify the number of engines that you would produce under
the exemption and the period during which you would produce them.
(iii) Information about the aircraft in which the engines will be
installed. Specify the airframe models and expected first purchasers/
users of the aircraft. Identify all countries in which you expect the
aircraft to be registered. Specify how many aircraft will be registered
in the United States and how many will be registered in other
countries; you may estimate this if it is not known.
(iv) A justification of why the exemption is appropriate.
Justifications must include a description of the environmental impact
of granting the exemption. Include other relevant information such as
the following:
(A) Technical issues, from an environmental and airworthiness
perspective, which may have caused a delay in compliance with a
production cutoff.
(B) Economic impacts on the manufacturer, operator(s), and aviation
industry at large.
(C) Environmental effects. This should consider the amount of
additional air pollutant emissions that will result from the exemption.
This could include consideration of items such as:
(1) The amount that the engine model exceeds the standard, taking
into account any other engine models in the engine type certificate
family covered by the same type certificate and their relation to the
standard.
(2) The amount of the applicable air pollutant that would be
emitted by an alternative engine for the same application.
(3) The impact of changes to reduce the applicable air pollutant on
other environmental factors, including emission rates of other air
pollutants, community noise, and fuel consumption.
(4) The degree to which the adverse impact would be offset by
cleaner engines produced in the same time period (unless we decide to
consider earlier engines).
(D) Impact of unforeseen circumstances and hardship due to business
circumstances beyond your control (such as an employee strike, supplier
disruption, or calamitous events).
(E) Projected future production volumes and plans for producing a
compliant version of the engine model in question.
(F) Equity issues in administering the production cutoff among
economically competing parties.
(G) List of other certificating authorities from which you have
requested (or expect to request) exemptions, and a summary of the
request.
(H) Any other relevant factors.
(v) A statement signed by your authorized representative attesting
that all information included in the request is accurate.
(2) In consultation with the EPA, the FAA may specify additional
conditions for the exemption.
(3) You must submit the annual report specified in paragraph (d) of
this section.
(4) The permanent record for each engine exempted under this
paragraph (a) must indicate that the engine is an exempted new engine.
(5) Engines exempted under this paragraph (a) must be labeled with
the following statement: ``EXEMPT NEW''.
(6) You must notify the FAA if you determine after submitting your
request that the information is not accurate, either from an error or
from changing circumstances. If you believe the new or changed
information could have affected approval of your exemption (including
information that could have affected the number of engines we exempt),
you must notify the FAA promptly. The FAA will consult with EPA as
needed to address any concerns related to this new or corrected
information.
(b) Temporary exemptions based on flights for short durations at
infrequent intervals. The emission standards of this part do not apply
to engines which power aircraft operated in the United States for short
durations at infrequent intervals. Such operations are limited to:
(1) Flights of an aircraft for the purpose of export to a foreign
country, including any flights essential to demonstrate the integrity
of an aircraft prior to its flight to a point outside the United
States.
(2) Flights to a base where repairs, alterations or maintenance are
to be performed, or to a point of storage, and flights for the purpose
of returning an aircraft to service.
(3) Official visits by representatives of foreign governments.
(4) Other flights the Secretary determines to be for short
durations at infrequent intervals. A request for such a determination
shall be made before the flight takes place.
(c) Spare engines. Newly manufactured engines meeting the
definition of ``spare engine'' are excepted as follows:
(1) This exception allows production of a newly manufactured engine
for installation on an in-service aircraft. It does not allow for
installation of a spare engine on a new aircraft.
(2) Each spare engine must be identical to a sub-model previously
certificated to meet all requirements applicable to Tier 4 engines or
later requirements.
(3) Spare engines excepted under this paragraph (c) may be used
only where the emissions of the spare engines are certificated to equal
to or lower emission standards than those of the engines they are
replacing, for all regulated pollutants.
(4) No prior approval is required to produce spare engines. Engine
manufacturers must include information about their production of spare
engines in the annual report specified in paragraph (d) of this section
(5) The permanent record for each engine excepted under this
paragraph (c) must indicate that the engine was produced as an excepted
spare engine.
(6) Engines excepted under this paragraph (c) must be labeled with
the following statement: ``EXCEPTED SPARE''.
(d) Annual reports. If you produce engines with an exemption/
exception under this section, you must submit an annual report with
respect to such engines.
(1) You must send the Designated EPA Program Officer a report
describing your production of exempted/excepted engines for each
calendar year in which you produce such engines by February 28 of the
following calendar year. You may include this information in the
certification report described in Sec. 87.42. Confirm that the
information in your initial request is still accurate, or describe any
relevant changes.
(2) Provide the information specified in this paragraph (d)(2). For
purposes of this paragraph (d), treat spare engine exceptions separate
from other new engine exemptions. Include the following for each
exemption/exception and each engine model and sub-model:
(i) Engine model and sub-model names.
(ii) Serial number of each engine.
(iii) Use of each engine (for example, spare or new installation).

[[Page 36386]]

(iv) Types of aircraft in which the engines were installed (or are
intended to be installed for spare engines).
(v) Serial number of the new aircraft in which engines are
installed (if known), or the name of the air carriers (or other
operators) using spare engines.
(3) Include information in the report only for engines having a
date of manufacture within the specific calendar year.

Subpart G--Test Procedures

0
13. The heading for subpart G is revised as set forth above.

0
14. Revise Sec. 87.60 to read as follows:

Sec. 87.60 Testing engines.

(a) Use the equipment and procedures specified in Appendix 3,
Appendix 5, and Appendix 6 of ICAO Annex 16 (incorporated by reference
in Sec. 87.8), as applicable, to demonstrate whether engines meet the
gaseous emission standards specified in subpart C of this part. Measure
the emissions of all regulated gaseous pollutants. Similarly, use the
equipment and procedures specified in Appendix 2 and Appendix 6 of ICAO
Annex 16 to determine whether engines meet the smoke standard specified
in subpart C of this part. The compliance demonstration consists of
establishing a mean value from testing some number of engines, then
calculating a ``characteristic level'' by applying a set of statistical
factors that take into account the number of engines tested. Round each
characteristic level to the same number of decimal places as the
corresponding emission standard. For turboprop engines, use the
procedures specified for turbofan engines, consistent with good
engineering judgment.
(b) Use a test fuel meeting the specifications described in
Appendix 4 of ICAO Annex 16 (incorporated by reference in Sec. 87.8).
The test fuel must not have additives whose purpose is to suppress
smoke, such as organometallic compounds.
(c) Prepare test engines by including accessories that are
available with production engines if they can reasonably be expected to
influence emissions. The test engine may not extract shaft power or
bleed service air to provide power to auxiliary gearbox-mounted
components required to drive aircraft systems.
(d) Test engines must reach a steady operating temperature before
the start of emission measurements.
(e) In consultation with the EPA, the FAA may approve alternate
procedures for measuring emissions as specified in this paragraph (e).
This might include testing and sampling methods, analytical techniques,
and equipment specifications that differ from those specified in this
part. Manufacturers and operators may request this approval by sending
a written request with supporting justification to the FAA and to the
Designated EPA Program Officer. Such a request may be approved only if
one of the following conditions is met:
(1) The engine cannot be tested using the specified procedures.
(2) The alternate procedure is shown to be equivalent to or better
(e.g., more accurate or precise) than the specified procedure.
(f) The following landing and take-off (LTO) cycles apply for
emission testing and calculating weighted LTO values:

Table 1 to Sec. 87.60--LTO Test Cycles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Turboprop Subsonic turbofan Supersonic turbofan
------------------------------------------------------------------------------------------------
Mode Percent of Time in mode Percent of Time in mode Percent of Time in mode
rated output (minutes) rated output (minutes) rated output (minutes)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Take-off............................................... 100 0.5 100 0.7 100 1.2
Climb.................................................. 90 2.5 85 2.2 65 2.0
Descent................................................ .............. .............. .............. .............. 15 1.2
Approach............................................... 30 4.5 30 4.0 34 2.3
Taxi/ground idle....................................... 7 26.0 7 26.0 5.8 26.0
--------------------------------------------------------------------------------------------------------------------------------------------------------

(g) Engines comply with an applicable standard if the testing
results show that the engine type certificate family's characteristic
level does not exceed the numerical level of that standard, as
described in Sec. 87.60.

Sec. Sec. 87.61-87.63 [Removed]

0
15. Remove Sec. Sec. 87.61-87.63.

Sec. 87.64 [Amended]

0
16. In Sec. 87.64, remove and reserve paragraph (a).

Sec. Sec. 87.65-87.71 [Removed]

0
17. Remove Sec. Sec. 87.65-87.71.

Subpart H--[Removed]

0
18. Remove subpart H.

PART 1068--GENERAL COMPLIANCE PROVISIONS FOR HIGHWAY, STATIONARY,
AND NONROAD PROGRAMS

0
19. The authority citation for part 1068 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A--[Amended]

0
20. Amend Sec. 1068.1 by revising paragraph (b) to read as follows:

Sec. 1068.1 Does this part apply to me?

* * * * *
(b) This part does not apply to any of the following engine or
vehicle categories:
(1) Light-duty motor vehicles (see 40 CFR part 86).
(2) Heavy-duty motor vehicles and motor vehicle engines, except as
specified in 40 CFR part 86.
(3) Aircraft engines, except as specified in 40 CFR part 87.
(4) Land-based nonroad compression-ignition engines we regulate
under 40 CFR part 89.
(5) Small nonroad spark-ignition engines we regulate under 40 CFR
part 90.
(6) Marine spark-ignition engines we regulate under 40 CFR part 91.
(7) Locomotive engines we regulate under 40 CFR part 92.
(8) Marine compression-ignition engines we regulate under 40 CFR
parts 89 or 94.
* * * * *
[FR Doc. 2012-13828 Filed 6-15-12; 8:45 am]
BILLING CODE 6560-50-P