[Federal Register Volume 78, Number 192 (Thursday, October 3, 2013)]
[Rules and Regulations]
[Pages 61168-61171]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-23448]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2013-0052; Directorate Identifier 2013-NE-02-AD;
Amendment 39-17600; AD 2013-19-18]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: We are adopting a new airworthiness directive (AD) for all
Rolls-Royce plc (RR) RB211-535E4-37, RB211-535E4-B-37, RB211-535E4-C-
37, and RB211-535E4-B-75 turbofan engines. This AD requires removal of
affected parts using a drawdown plan. This AD was prompted by RR
updating the low-cycle-fatigue life analysis for the low pressure
turbine (LPT) stage 2 discs. We are issuing this AD to prevent LPT
stage 2 disc failure, which could result in uncontained engine damage
and damage to the airplane.
DATES: This AD becomes effective November 7, 2013. The Director of the
Federal Register approved the incorporation by reference of certain
publications listed in this AD as of November 7, 2013.
ADDRESSES: The Docket Operations office is located at Docket Management
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the mandatory continuing
airworthiness information (MCAI), the regulatory evaluation, any
comments received, and other information. The street address for the
Docket Operations office (phone: 800-647-5527) is provided in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Robert Green, Aerospace Engineer,
Engine Certification Office, FAA, Engine & Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803; phone: 781-238-7754;
fax: 781-238-7199; email: [email protected].
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to the specified products. The
NPRM was published in the Federal Register on April 5, 2013 (78 FR
20507). The NPRM proposed to correct an unsafe condition for the
specified products. The MCAI states:
A recent re-evaluation of Critical Part lives carried out by
Rolls-Royce revealed changes to the thermal profile and stresses in
certain features of the low pressure turbine (LPT) Stage 2 disc.
These changes have resulted in a reduction of the cyclic life of the
LPT stage 2 discs.
Operation of an engine equipped with a Critical Part that has
exceeded its cyclic life may result in Critical Part failure,
consequent release of high energy debris, damage to the aeroplane
and/or injury to occupants.
Comments
We gave the public the opportunity to participate in developing
this AD. We considered the comments received.
Agreement With the AD
The Boeing Company expressed support for the NPRM (78 FR 20507,
dated April 5, 2013).
Request To Be Less Specific About Service Bulletin Revision Level and
Date
Texas Aero Engine Services LLC and United Airlines (UAL) requested
that we not include the revision level and date of RR Alert Non-
Modification Service Bulletin (NMSB) No. RB.211-72-AH029, dated
December 13, 2012, or that we add the words ``or later revision''
because service bulletins can be revised often.
We disagree. RR Alert NMSB No. RB.211-72-AH029, dated December 13,
2012, contains unique methods that require incorporation by reference,
requiring that we specify revision level and date. We do not know how
the NMSB may be revised in the future, and therefore cannot add the
words ``or later revision.'' We did not change this AD.
Request To Change the Definition of Engine Shop Visit (ESV)
RR and UAL requested that we change our definition of ESV in
paragraph (g) of this AD by replacing the words ``separation of
flanges'' with ``deblading of the affected rotor disc.'' They noted
that our ESV definition is not consistent with the instructions in RR
Alert NMSB No. RB.211-72-AH029, dated December 13, 2012, which only
applies when the LPT Module will be stripped and the affected rotor is
debladed. Our ESV
[[Page 61169]]
definition will result in removal of parts earlier than would occur
using the RR NMSB. RR noted that this is unnecessary based on their
risk assessment of a possible failure. In a subsequent comment, RR
asked that the ESV definition be based on the deblading of the high
pressure turbine disc since this better defines an engine refurbishment
shop visit.
We disagree. We defined ESV as the separation of a pair of major
mating engine module flanges in order to satisfy our safety concerns
while minimizing the impact to the public. We have determined that
corrective actions can be practicably implemented at next ESV and that
these actions will provide an acceptable level of safety. We did not
change this AD.
Request To Exempt an External Gearbox Removal From the ESV Definition
RR requested that we clarify that the separation of a pair of major
mating engine module flanges in paragraph (g) of this AD does not
include the separation of an engine external gearbox from the engine,
which would not constitute a refurbishment shop visit.
We agree. We changed paragraph (g) of this AD to state: ``For the
purpose of this AD, an ESV is whenever engine maintenance performed
prior to reinstallation requires the separation of a pair of major
mating engine module flanges. Separation of flanges solely for the
purpose of shipment without subsequent internal maintenance is not an
ESV. Separation of the external gearbox engine mating flanges or
removal of the external gearbox is also not classified as a shop
visit.''
Request To Delay Implementation of Reduced Rotating Parts Life Limits
American Airlines (AAL), FedEx Express, and RR asked that we revise
or remove paragraph (e)(2) of this AD to eliminate the requirement to
assign the reduced maximum approved lives within 30 days of the
effective date of this AD and allow the current lives as published in
the Time Limits Manual (TLM) to remain in effect until November 30,
2016. AAL stated that the AD requirement will cause problems for
operator life limit tracking systems, causing confusion and possibly
the grounding of aircraft. Operator life limit tracking systems prevent
the operation of parts beyond their maximum approved lives.
We disagree. Operating beyond the redefined, reduced cyclic life
limits represents an unsafe condition. LPT stage 2 discs that exceed
the reduced life limits should be removed from service as soon as
practicable to correct an unsafe condition. We did not change this AD.
Request To Clarify Wording Regarding Compliance Date and Life Limits
AAL and RR requested that we clarify wording in paragraph (e)(4) of
this AD regarding removal of affected parts by the compliance date, and
that the parts cannot exceed current life limits. AAL stated that this
paragraph could potentially allow parts to operate beyond both the
current and reduced life limits.
We partially agree. We agree that paragraph (e)(4) of this AD could
be misinterpreted because we did not specify that paragraph (e)(3) of
this AD applies to those engines which have an engine shop visit prior
to reaching the reduced life.
We do not agree that the compliance wording could potentially allow
parts to operate beyond their current life limits because the TLM
limits for the RR RB211 engine cannot be exceeded.
We changed paragraph (e)(3) of this AD by inserting ``before
reaching the part life assigned in paragraph (e)(2)''. The paragraph
now reads: ``(3) After the effective date of this AD, for engines that
have an engine shop visit (ESV) before reaching the part life assigned
in paragraph (e)(2) of this AD, remove the LPT stage 2 disc from
service before the part exceeds the part life assigned in paragraph
(e)(2).''
Request To Change Compliance To Be Consistent With the RR Alert NMSB
AAL, RR, and UAL requested that we change the compliance to be
consistent with RR Alert NMSB No. RB.211-72-AH029, dated December 13,
2012. This AD requires that the reduced life limits be assigned within
30 days after the effective date of the AD. The RR Alert NMSB
establishes that these lives are provisional lives, and that the
current lives as published in the TLM remain in effect until November
30, 2016. AAL and RR noted that the risk assessment conducted by RR
supports the continued use of the current life limits for parts not
exposed during a shop visit and demonstrated an acceptable level of
safety. AAL noted that the AD as proposed (78 FR 20507, April 5, 2013)
will result in significant shop visit costs in comparison to the shop
visit costs associated with the RR Alert NMSB.
We disagree. The redefined, reduced cyclic life limits are needed
to correct an unsafe condition. We have determined that corrective
actions can be practicably implemented at next ESV and that these
actions will provide an acceptable level of safety. We did not change
this AD.
Request To Change Compliance Time
UAL requested that we change the compliance time in paragraphs
(e)(1) and (e)(2) of this AD from ``within 30 days'' to ``within 90
days'' because for UAL's fleet of 137 engines, 30 days is too short of
a compliance period.
We disagree. The recommended timeframe for completion in RR Alert
NMSB No. RB.211-72-AH029, dated December 13, 2012, was 6 weeks. The new
lives of the LPT stage 2 discs could have been recalculated starting
from when the NMSB was issued. In addition, the effective date of this
AD is 35 days after the date of publication in the Federal Register,
which provides additional time beyond the 30 days mandated in this AD.
We did not change this AD.
Request To Change the Costs of Compliance
AAL requested that we change the costs of compliance to include the
labor costs associated with replacing the parts at an ESV (i.e., engine
disassembly costs). AAL states that the AD requires replacement of
parts in modules that are not related to an engine removal cause, which
will result in additional labor costs to access and replace those
parts.
We disagree. We consider the actual costs of this AD, which are
associated with the prorated reduction in the lives of the life-limited
parts. We do not consider the engine disassembly costs that will vary
depending on the category of the ESV. We did not change this AD.
Comment That the European Aviation Safety Agency (EASA) AD Referred to
in the NPRM Has Been Superseded
RR commented that EASA AD 2012-0266, dated December 18, 2012,
referred to in this AD, has been superseded.
We disagree. EASA AD 2012-0266 is not superseded. We did not change
this AD.
Conclusion
We reviewed the available data, including the comments received,
and determined that air safety and the public interest require adopting
this AD with the changes described previously. We determined that these
changes will not increase the economic burden on any operator or
increase the scope of this AD.
Costs of Compliance
We estimate that this AD would affect about 220 engines installed
on airplanes of U.S. registry. The average labor rate is $85 per hour.
We do not estimate any
[[Page 61170]]
labor cost associated with this AD because the affected parts are
replaced during scheduled shop visits. Prorated cost of the parts
adjusted for lost life is about $8,290 per engine. Based on these
figures, we estimate the cost of the AD on U.S. operators to be
$1,823,800.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. ``Subtitle VII: Aviation
Programs,'' describes in more detail the scope of the Agency's
authority.
We are issuing this rulemaking under the authority described in
``Subtitle VII, Part A, Subpart III, Section 44701: General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We determined that this AD will not have federalism implications
under Executive Order 13132. This AD will not have a substantial direct
effect 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.
For the reasons discussed above, I certify this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska to the extent
that it justifies making a regulatory distinction, and
(4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
2013-19-18 Rolls-Royce plc: Amendment 39-17600; Docket No. FAA-2013-
0052; Directorate Identifier 2013-NE-02-AD.
(a) Effective Date
This AD becomes effective November 7, 2013.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Rolls-Royce plc (RR) RB211-535E4-37,
RB211-535E4-B-37, RB211-535E4-C-37, and RB211-535E4-B-75 turbofan
engines.
(d) Unsafe Condition
This AD was prompted by RR updating the low-cycle-fatigue life
analysis for the low pressure turbine (LPT) stage 2 discs. We are
issuing this AD to prevent LPT stage 2 disc failure, which could
result in uncontained engine damage and damage to the airplane.
(e) Actions and Compliance
(1) Within 30 days after the effective date of this AD, re-
calculate the cyclic life since new of each LPT stage 2 disc. Use
the part lives and prorated life formulas in Appendices 1, 2, and 3
of RR Alert Non-Modification Service Bulletin (NMSB) No. RB.211-72-
AH029, dated December 13, 2012, to make that calculation.
(2) Assign the Maximum Approved Lives defined in Appendix 1 of
Alert NMSB No. RB.211-72-AH029, dated December 13, 2012, to the LPT
stage 2 disc based on the flight profile that will be flown.
(3) After the effective date of this AD, for engines that have
an engine shop visit (ESV), before reaching the part life assigned
in paragraph (e)(2) of this AD, remove the LPT stage 2 disc from
service before the part exceeds the part life assigned in paragraph
(e)(2).
(4) For those engines that do not have an ESV after the
effective date of this AD before the part exceeds the part life
assigned in paragraph (e)(2) of this AD, remove the part from
service at the next ESV.
(f) Installation Prohibition
Except for parts that have been reworked using RR Service
Bulletin No. RB.211-72-D365, Revision 5, dated December 13, 2012,
after the effective date of this AD, do not reinstall any part
removed per this AD into any engine.
(g) Definition
For the purpose of this AD, an ESV is whenever engine
maintenance performed prior to reinstallation requires the
separation of a pair of major mating engine module flanges.
Separation of flanges solely for the purpose of shipment without
subsequent internal maintenance is not an ESV. Separation of the
external gearbox engine mating flanges or removal of the external
gearbox is also not classified as a shop visit.
(h) Alternative Methods of Compliance (AMOCs)
The Manager, Engine Certification Office, FAA, may approve AMOCs
to this AD. Use the procedures found in 14 CFR 39.19 to make your
request.
(i) Related Information
(1) For more information about this AD, contact Robert Green,
Aerospace Engineer, Engine Certification Office, FAA, Engine &
Propeller Directorate, 12 New England Executive Park, Burlington, MA
01803; phone: 781-238-7754; fax: 781-238-7199; email:
[email protected].
(2) Refer to European Aviation Safety Agency Airworthiness
Directive 2012-0266, dated December 18, 2012 for more information.
You may examine the AD on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2013-0052-0004.
(j) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) RR Alert Non-Modification Service Bulletin (NMSB) No.
RB.211-72-AH029, dated December 13, 2012.
(ii) Reserved.
(3) For Rolls-Royce plc service information identified in this
AD, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31,
Derby, England, DE248BJ; phone: 011-44-1332-242424; fax: 011-44-
1332-249936; email: http://www.rolls-royce.com/contact/civil_team.jsp; or download from https://www.aeromanager.com.
(4) You may view this service information at FAA, Engine &
Propeller Directorate, 12 New England Executive Park, Burlington,
MA. For information on the availability of this material at the FAA,
call 781-238-7125.
(5) You may view this service information 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/cfr/ibr-locations.html.
[[Page 61171]]
Issued in Burlington, Massachusetts, on September 16, 2013.
Carlos A. Pestana,
Acting Directorate Assistant Manager, Engine & Propeller Directorate,
Aircraft Certification Service.
[FR Doc. 2013-23448 Filed 10-2-13; 8:45 am]
BILLING CODE 4910-13-P