AD 98-14-06

This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace BAe Model ATP airplanes. This amendment requires repetitive inspections for discrepancies of the spring strut assembly of the forward door of the main landing gear (MLG), and replacement of the existing spring strut assembly with a new or serviceable part, if necessary. This amendment also requires eventual replacement of the existing spring strut assembly with an improved part, which, when accomplished, terminates the repetitive inspections. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the spring strut assembly of the forward door of the MLG, which, if not corrected, could result in inability to extend the MLG.

Final rule

98-14-06 BRITISH AEROSPACE REGIONAL AIRCRAFT [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Amendment 39-10640. Docket 98-NM-113-AD.
Applicability: BAe Model ATP airplanes, as listed in British Aerospace Alert Service Bulletin ATP-32-85, Revision 1, dated March 20, 1998; 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 hasnot been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the spring strut assembly of the forward door of the main landing gear (MLG), which could result in the inability to extend the MLG, accomplish the following:

(a) Within 600 flight hours after the effective date of this AD, perform a visual inspection for discrepancies of the fork end of the spring strut assembly of the forward door of the MLG, on the left and right sides of the airplane; in accordance with British Aerospace Alert Service Bulletin ATP-32-85, Revision 1, dated March 20, 1998.

(1) If no discrepancy is detected, repeat the visual inspection thereafter at intervals not to exceed 1,500 flight hours until the actions specified by paragraph (b) of this AD are accomplished.

(2) If any discrepancy is detected, prior to further flight, replace the existing spring strut assembly with a new or serviceable part, in accordance with the alert service bulletin. Repeat the visual inspection thereafter at intervals not to exceed 1,500 flight hours until the actions specified by paragraph (b) of this AD are accomplished.

(b) Within 18 months after the effective date of this AD, replace the spring strut assembly of the forward door of the MLG with an improved spring strut assembly, on the left and right sides of the airplane; in accordance with British Aerospace Service Bulletin ATP-32-87, dated January 29, 1998. This replacement constitutes terminating action for the requirements 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 request 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.

(e) The replacement shall be done in accordance with British Aerospace Service Bulletin ATP-32-87, dated January 29, 1998. The inspection shall be done in accordance with British Aerospace Alert Service Bulletin ATP-32-85, Revision 1, dated March 20, 1998, which contains the following effective pages:

Page Number
Shown on Page
Revision Level
Shown on Page
Date
Shown on Page
1-3, 6, 7, 10
1
March 20, 1998
4, 5, 8, 9, 11
Original
January 26, 1998

This incorporation by reference was approved bythe Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from AI(R) American Support, Inc., 13850 McLearen Road, Herndon, Virginia 20171. 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.

(f) This amendment becomes effective on August 5, 1998.

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 British Aerospace BAe Model ATP airplanes was published in the Federal Register on May 1, 1998 (63 FR 24136). That action proposed to require repetitive inspections for discrepancies of the spring strut assembly of the forward door of the main landing gear (MLG), and replacement of the existing spring strut assembly with a new or serviceable part, if necessary. That action also proposed to require eventual replacement of the existing spring strut assembly with an improved part, which, when accomplished, would terminate the repetitive inspections.

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 10 airplanes of U.S. registry will be affected by this AD.

It will take approximately 4 work hours (2 work hours per MLG) to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on this figure, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $2,400, or $240 per airplane, per inspection cycle.

It will take approximately 12 work hours (6 work hours per MLG) to accomplish the required modification, at an average labor rate of $60 per work hour. Required parts will cost approximately $2,200 per airplane ($1,100 per MLG). Based on this figure, the cost impact of the modification required by this AD on U.S. operators is estimated to be $29,200, or $2,920 per airplane.

The cost impact figures discussed above are 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.

Regulatory Impact
The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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 of the 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: