[Federal Register Volume 68, Number 242 (Wednesday, December 17, 2003)]
[Proposed Rules]
[Pages 70208-70210]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-31066]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-116-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR42 and 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 ATR42 
and ATR72 series airplanes. This proposal would require replacement of 
the swinging lever spacers in the left and right leg assemblies of the 
main landing gear with new, improved spacers. This action is necessary 
to prevent propagation of fatigue cracking, which could result in 
failure of the spacer base and could affect the symmetrical functioning 
of the braking system. Asymmetrical braking could result in the 
airplane overrunning the runway during takeoff or landing. This action 
is intended to address the identified unsafe condition.

DATES: Comments must be received by January 16, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

[[Page 70209]]

Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-116-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-116-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 or 2000 or 
ASCII text.
    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: Tony Jopling, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2190; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NM-116-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. 2002-NM-116-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 ATR42 and ATR72 
series airplanes. The DGAC advises that several cases of fatigue 
cracking have been found on the swinging lever spacers in the main 
landing gear (MLG). The fatigue cracking is located at the intersection 
base of the spacer, and is due to a stress concentration. Propagation 
of such cracking could result in failure of the spacer base and could 
affect the symmetrical functioning of the braking system. Asymmetrical 
braking could result in the airplane overrunning the runway during 
takeoff or landing.

Explanation of Relevant Service Information

    The manufacturer has issued Avions de Transport Regional Service 
Bulletins ATR42-32-0094 and ATR72-32-1042, both dated November 26, 
2001. The Avions de Transport Regional Service Bulletins reference 
Messier-Dowty Service Bulletins 631-32-166, dated November 28, 2001 
(for Model ATR42 series airplanes); and 631-32-165, dated November 27, 
2001 (for Model ATR72 series airplanes) for accomplishment of the 
replacement of the swinging lever spacers of the MLG. The Messier-Dowty 
service bulletins describe procedures for replacement of the swinging 
lever spacers in the left and right leg assemblies of the MLG with new, 
improved spacers. The new spacers were manufactured using 7175 
material, which is stronger than the 2024 and 7010 material used in the 
existing spacers. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition. The DGAC classified the Avions de Transport Regional 
service bulletins as mandatory and issued French airworthiness 
directives 2001-614-089(B) and 2001-615-062(B), both dated December 26, 
2001, to ensure the continued airworthiness of these airplanes in 
France.

FAA's Conclusions

    These airplane models are manufactured in France and are 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 us informed of the 
situation described above. We have 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 AD

    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 information described previously, 
except as discussed below.

Differences Among French Airworthiness Directive, Service Information, 
and Proposed AD

    The applicability specified in French airworthiness directive 2001-
614-089(B) includes Aerospatiale Model ATR42-400; however, this 
proposed AD does not include that model because no U.S. type 
certificate has been issued for that airplane.
    Paragraph 1.C.(4) of service bulletin ATR42-32-0094 references 
Messier-Dowty Service Bulletin No. 631-32-165 for the replacement of 
the swinging lever spacers of the MLG; however, the correct number for 
that service bulletin is No. 631-32-166. The manufacturer has been 
notified of this typographical error and will be issuing a revised 
service bulletin.

Cost Impact

    The FAA estimates that 133 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take about

[[Page 70210]]

16 work hours per airplane to accomplish the proposed replacement, and 
that the average labor rate is $65 per work hour. Required parts would 
cost between $921 and $4,272 per airplane. Based on these figures, the 
cost impact of the proposed replacement on U.S. operators is estimated 
to be between $1,961 and $5,312 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. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations proposed herein would 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 levers of government. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 2002-NM-116-AD.

    Applicability: Model ATR42-200, -300, -320, and -500 series 
airplanes on which ATR Modification 5338 has not been done; and 
Model ATR72-101, -102, -201, -202, -211, -212, and -212A series 
airplanes on which ATR Modification 5337 has not been done; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the spacer base of the swinging lever 
spacers in the left and right leg assemblies of the main landing 
gear (MLG) and consequent asymmetrical braking, which could result 
in the airplane overrunning the runway during takeoff or landing, 
accomplish the following:

Replacement

    (a) Replace the swinging lever spacers in the left and right leg 
assemblies of the MLG with new, improved spacers, per Avions de 
Transport Regional Service Bulletins ATR42-32-0094 and ATR72-32-
1042, both dated November 26, 2001. Do the replacement at the 
applicable time specified in paragraphs (a)(1) or (a)(2) of this AD.
    (1) For Model ATR42-200, -300, and -320, and Model ATR72-101, -
102, -201, -202, -211, -212, and -212A series airplanes: Do the 
replacement at the later of the times specified in paragraphs 
(a)(1)(i) and (a)(1)(ii) of this AD.
    (i) Before the accumulation of 15,000 total landings or 8 years 
in-service on new or overhauled swinging lever spacers, whichever is 
first.
    (ii) Within 3,000 landings after the effective date of this AD.
    (2) For Model ATR42-500 series airplanes: Do the replacement 
before the accumulation of 18,000 total landings or 9 years in-
service on new or overhauled swinging lever spacers, whichever is 
first.
    (b) Messier-Dowty Service Bulletins 631-32-166, dated November 
28, 2001 (for Model ATR42 series airplanes); and 631-32-165, dated 
November 27, 2001 (for Model ATR72 series airplanes), may be used 
for accomplishment of the replacement required by paragraph (a) of 
this AD.

Alternative Methods of Compliance

    (c) In accordance with 14 CFR 39.19, the Manager, International 
Branch, ANM-116, FAA, Transport Airplane Directorate, is authorized 
to approve alternative methods of compliance for this AD.

    Note 1: The subject of this AD is addressed in French 
airworthiness directives 2001-614-089(B) and 2001-615-062(B), both 
dated December 26, 2001.


    Issued in Renton, Washington, on December 5, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-31066 Filed 12-16-03; 8:45 am]
BILLING CODE 4910-13-P