[Federal Register Volume 63, Number 24 (Thursday, February 5, 1998)]
[Proposed Rules]
[Pages 5900-5902]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-2782]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-263-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 certain Aerospatiale Model ATR72
series airplanes. This proposal would require a one-time high frequency
eddy current inspection to detect cracking of the lower fuselage
structure, and repair, if necessary. This proposal also would require
modification of certain fastener holes in the lower fuselage structure.
This proposal is prompted by the issuance of mandatory continuing
airworthiness information by a foreign civil airworthiness authority.
The actions specified by the proposed AD are intended to prevent
reduced structural integrity of the airplane due to fatigue cracking in
the lower fuselage structure.
DATES: Comments must be received by March 9, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-263-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-263-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-263-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, notified the FAA that an unsafe
condition may exist on certain Aerospatiale Model ATR72 series
airplanes. The DGAC advises that the results of full-scale fatigue
testing on a Model ATR72 test article revealed that fatigue cracks may
develop in the lower
[[Page 5901]]
fuselage structure in the area of the side brace fitting near frame 25.
Such fatigue cracking, if not detected and corrected in a timely
manner, could result in reduced structural integrity of the airplane.
Explanation of Relevant Service Information
Aerospatiale has issued Service Bulletins ATR72-53-1022, Revision
2, dated February 20, 1995; ATR72-53-1034, Revision 1, dated March 28,
1995; and ATR72-53-1053, Revision 1, dated March 28, 1995. These
service bulletins describe procedures for a one-time high frequency
eddy current inspection to detect cracking of the lower fuselage
structure; and modification of certain fastener holes in the lower
fuselage structure in the area of the side brace fitting near frame 25
on the left- and right-hand sides. Accomplishment of the actions
specified in these service bulletins is intended to adequately address
the identified unsafe condition. The DGAC classified these service
bulletins as mandatory and issued French airworthiness directive 94-
191-022(B), dated August 17, 1994, 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 DGAC has kept the FAA informed
of the situation described above. The FAA has examined the findings of
the 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.
Explanation of Requirements of 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 accomplishment of
the actions specified in the service bulletins described previously;
except that the repair of any crack or oversize hole would be required
to be accomplished in accordance with a method approved by the FAA.
Cost Impact
The FAA estimates that 7 airplanes of U.S. registry would be
affected by this proposed AD.
Accomplishment of the actions specified in Aerospatiale Service
Bulletin ATR72-53-1022 would take approximately 80 work hours per
airplane, at an average labor rate of $60 per work hour. Required parts
would be provided by the manufacturer at no cost to the operators.
Based on these figures, the cost impact on U.S. operators of the
actions specified in this service bulletin and proposed by this AD is
estimated to be $4,800 per airplane.
Accomplishment of the actions specified in Aerospatiale Service
Bulletin ATR72-53-1034 would take approximately 65 work hours per
airplane, at an average labor rate of $60 per work hour. Required parts
would be provided by the manufacturer at no cost to the operators.
Based on these figures, the cost impact on U.S. operators of the
actions specified in this service bulletin and proposed by this AD is
estimated to be $3,900 per airplane.
Accomplishment of the actions specified in Aerospatiale Service
Bulletin ATR72-53-1053 would take approximately 65 work hours per
airplane, at an average labor rate of $60 per work hour. Required parts
would be provided by the manufacturer at no cost to the operators.
Based on these figures, the cost impact on U.S. operators of the
actions specified in this service bulletin and proposed by this AD is
estimated to be $3,900 per airplane.
The cost impact figures discussed above are 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:
Aerospatiale: Docket 97-NM-263-AD.
Applicability: Model ATR72 series airplanes on which
Aerospatiale Modification 2879 or Modification 2628 has not been
incorporated, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 prevent reduced structural integrity of the airplane due to
fatigue cracking in the lower fuselage structure, accomplish the
following:
(a) Prior to the accumulation of 17,500 total flight cycles, or
within 500 flight cycles after the effective date of this AD,
whichever occurs later: Except as provided in paragraph (b) of this
AD, perform a one-time high frequency eddy current inspection to
detect fatigue cracking around the fastener holes in the lower
fuselage structure in the area of the
[[Page 5902]]
side brace fitting near frame 25 on the left-and right-hand sides,
and modify crack-free fastener holes, as required by paragraph
(a)(1) and/or (a)(2) of this AD, as applicable.
(1) For airplanes on which Aerospatiale Modification 2879 has
not been installed: Perform the inspection and modification in
accordance with Aerospatiale Service Bulletin ATR72-53-1022,
Revision 2, dated February 20, 1995.
(2) For airplanes on which Aerospatiale Modification 2628 has
not been installed: Perform the inspection and modifications in
accordance with Aerospatiale Service Bulletins ATR72-53-1034,
Revision 1, and ATR72-53-1053, Revision 1, both dated March 28,
1995.
(b) If any crack or oversize hole is found during the
accomplishment of paragraph (a) of this AD, and if any service
bulletin listed in paragraph (a) of this AD specifies to contact the
manufacturer for an appropriate corrective action: Prior to further
flight, repair the discrepancy in accordance with a method approved
by the Manager, International Branch, ANM-116, FAA, Transport
Airplane Directorate.
(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.
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 directive 94-191-022(B), dated August 17, 1994.
Issued in Renton, Washington, on January 29, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-2782 Filed 2-4-98; 8:45 am]
BILLING CODE 4910-13-U
