AD 2004-03-18

This amendment adopts a new airworthiness directive (AD), applicable to certain Aerospatiale Model ATR42 and ATR72 series airplanes, that requires 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.

Final rule.

2004-03-18 Aerospatiale: Amendment 39-13462. 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 Bulletin ATR42-32-0094 or ATR72-32-1042, both dated November 26, 2001, as applicable. Do the replacement at the applicable time specified in paragraph (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 Bulletin 631-32-166, dated November 28, 2001 (for Model ATR42 series airplanes); or 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.

Incorporation by Reference

(d) Unless otherwise specified in this AD, the actions shall be done in accordance with Avions de Transport Regional Service Bulletin ATR42-32-0094, dated November 26, 2001; or Avions de Transport Regional Service Bulletin ATR72-32-1042, dated November 26, 2001; as applicable. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

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.

Effective Date

(e) This amendment becomes effective on March 17, 2004.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Aerospatiale Model ATR42 and ATR72 series airplanes was published in the Federal Register on December 17, 2003 (68 FR 70208). That action proposed to require replacement of the swinging lever spacers in the left and right leg assemblies of the main landing gear with new, improved spacers.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

The FAA estimates that 133 airplanes of U.S. registry will be affected by this AD, that it will take about 16 work hours per airplane to accomplish thereplacement, and that the average labor rate is $65 per work hour. Required parts will cost between $921 and $4,272 per airplane. Based on these figures, the cost impact of the 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 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 adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption ofthe Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: