[Federal Register Volume 64, Number 148 (Tuesday, August 3, 1999)]
[Proposed Rules]
[Pages 42054-42056]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-19808]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-273-AD]
RIN 2120-AA64
Airworthiness Directives; Aerospatiale Model ATR72 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to all Aerospatiale Model ATR72
series airplanes. This proposal would require a revision to the
Airworthiness Limitations Section of the Instructions for Continued
Airworthiness to incorporate inspections to detect fatigue cracking in
certain structure, inspection intervals, and life limits for certain
components. This proposal is prompted by issuance of mandatory
continuing airworthiness information by a foreign civil airworthiness
authority. The actions specified by the proposed AD are intended to
ensure that fatigue cracking of certain structural elements are
detected and corrected; such fatigue cracking could adversely affect
the structural integrity of these airplanes.
DATES: Comments must be received by September 17, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-273-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex
03, France. This information may be examined at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-273-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 97-NM-273-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Direction Generale de l'Aviation Civile (DGAC), which is the
airworthiness authority for France, has notified the FAA that an unsafe
condition may exist on Aerospatiale Model ATR72 series airplanes. The
DGAC advises that analysis of fatigue test data has revealed that
certain inspections must be performed at specific intervals to preclude
fatigue cracking in certain areas of the airplane. Additionally,
certain life limits must be imposed for various components on these
airplanes to preclude the onset of fatigue cracking in those
components.
Fatigue cracking of certain structural elements, if not detected
and corrected in a timely manner, could adversely affect the structural
integrity of these airplanes.
Description of Service Information
Aerospatiale has issued ATR72 Maintenance Planning Document (MPD),
``Time Limits,'' Revision 1, dated February 1996, which includes the
following:
1. Life limit times for certain structural components or parts of
the nose landing gear, the main landing gear, the main landing gear
support structure, engine components, and various equipment. And
2. Structural inspection times to detect fatigue cracking of
certain Structural Significant Items (SSI's).
[[Page 42055]]
Performing the specified structural inspections will identify
fatigue cracking, and revising the component life limits will preclude
the onset of fatigue cracking of certain structural elements of the
airplane.
The French DGAC has classified Revision 1 of the Time Limits
section of the Aerospatiale Model ATR72 Maintenance Planning Document,
dated February 1996, as mandatory, and has issued French airworthiness
directive 95-105-026(B), dated May 24, 1995, in order to assure the
continued airworthiness of these airplanes in France.
FAA's Conclusions
This airplane model is manufactured in France and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the French DGAC has kept the FAA
informed of the situation described above. The FAA has examined the
findings of the French DGAC, reviewed all available information, and
determined that AD action is necessary for products of this type design
that are certificated for operation in the United States.
Description of the Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require a revision to the
Airworthiness Limitations Section of the Instructions for Continued
Airworthiness [Aerospatiale refers to this as the maintenance planning
document (MPD)] to incorporate inspections to detect fatigue cracking
of certain SSI's. The proposed AD also would revise life limits for
certain equipment and various components that are specified in the Time
Limits section of the ATR72 Airworthiness Limitations of the
Maintenance Planning Document, dated February 15, 1996.
Explanation of Action Taken by the FAA
In accordance with airworthiness standards requiring ``damage
tolerance assessments'' [reference current section 1529 of parts 23,
25, 27, and 29 of the Federal Aviation Regulations (FAR); section 4 of
parts 33 and 35 of the FAR; section 82 of part 31 of the FAR; and the
Appendices referenced in those sections], all products certificated to
comply with those sections must have Instructions for Continued
Airworthiness (or, for some products, maintenance manuals), that
include an Airworthiness Limitations Section. That section must set
forth:
Mandatory replacement times for structural components,
Structural inspection intervals, and
Related approved structural inspection procedures
necessary to show compliance with the damage-tolerance requirements.
Compliance with the terms specified in the Airworthiness
Limitations Sections is required by sections 43.16 (for persons
maintaining products) and 91.403 (for operators) of the FAR.
In order to require compliance with these inspection intervals and
life limits, the FAA must engage in rulemaking, namely the issuance of
an AD. For products certificated to comply with the referenced part 25
requirements, it is within the authority of the FAA to issue an AD
requiring a revision to the Airworthiness Limitations Section that
includes reduced life limits, or new or different structural inspection
requirements. These revisions then are mandatory for operators under
section 91.403(c) of the FAR, which prohibits operation of an airplane
for which Airworthiness Limitations have been issued unless the
inspection intervals specified in those limitations have been complied
with.
Once that document is revised, as required, and the AD has been
fully complied with, the life limit or structural inspection change
remains enforceable as a part of the Airworthiness Limitations. (This
is analogous to AD's that require changes to the Limitations Section of
the Airplane Flight Manual.)
Requiring a revision of the Airworthiness Limitations, rather than
requiring individual inspections, is advantageous for operators because
it allows them to record AD compliance status only once--at the time
they make the revision--rather than after every inspection. It also has
the advantage of keeping all Airworthiness Limitations, whether imposed
by original certification or by AD, in one place within the operator's
maintenance program, thereby reducing the risk of non-compliance
because of oversight or confusion.
Cost Impact
There are approximately 173 Aerospatiale Model ATR72 series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 39 airplanes of U.S. registry would be affected by this
proposed AD, that it would take approximately 1 work hour per airplane
to accomplish the proposed actions, and that the average labor rate is
$60 per work hour. Based on these figures, the cost impact of the
proposed AD on U.S. operators is estimated to be $2,340, or $60 per
airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would 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. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
regulation (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);
and (3) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ``ADDRESSES.''
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (14 CFR part 39) as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
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]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
[[Page 42056]]
Aerospatiale: Docket 97-NM-273-AD.
Applicability: All Model ATR72 series airplanes, certificated in
any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (c) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To ensure continued structural integrity of these airplanes,
accomplish the following:
(a) Within 30 days after the effective date of this AD, revise
the Airworthiness Limitations Section of the Instructions for
Continued Airworthiness in accordance with Section 9, ``Time
Limits,'' of the ATR72 Maintenance Planning Document, Revision 1,
dated February 1996. This may be accomplished by inserting a copy of
Section 9, ``Time Limits,'' of the ATR72 Maintenance Planning
Document, Revision 1, dated February 1996, into the Airworthiness
Limitations Section of the Instructions for Continued Airworthiness.
(b) Except as provided in paragraph (c) of this AD: After the
actions specified in paragraph (a) of this AD have been
accomplished, no alternative inspections or inspection intervals may
be approved for the structural elements specified in the documents
listed in paragraph (a) of this AD.
(c) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, International Branch, ANM-116, FAA
Transport Airplane Directorate. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager, International
Branch, ANM-116.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(d) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Note 3: The subject of this AD is addressed in French
airworthiness directives 95-105-026 (B), dated May 24, 1995.
Issued in Renton, Washington, on July 27, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-19808 Filed 8-2-99; 8:45 am]
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