AD 98-12-25

This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace BAe Model ATP airplanes, that requires a one-time inspection to detect corrosion, wear, or damage of the operating mechanism of the forward door of the main landing gear (MLG); operational inspections to ensure smooth operation of the MLG operating mechanism; and follow-on actions. 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 partial seizure of the forward door of the MLG operating mechanism, which could result in the inability to lower or retract the MLG.

Final rule

98-12-25 BRITISH AEROSPACE REGIONAL AIRCRAFT [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Amendment 39-10579. Docket 97-NM-312-AD.
Applicability: BAe Model ATP airplanes, constructor s numbers 2001 through 2063 inclusive; 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 (d) 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 includespecific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent partial seizure of the forward door of the main landing gear (MLG) operating mechanism, which could result in the inability to lower or retract the MLG, accomplish the following:

(a) Within 300 flight hours or within 90 days after the effective date of this AD, whichever occurs first, perform a one-time visual inspection to detect corrosion, wear, or damage of the operating mechanism of the forward door of the MLG; and clean, degrease, and relubricate the door operating mechanism; in accordance with British Aerospace Service Bulletin ATP-32-84, Revision 1, dated September 26, 1997.

(1) If no corrosion, wear, or damage is detected during the inspection required by paragraph (a) of this AD, no further action is required by this AD.

(2) If any corrosion, damage, or worn component is detected during the inspection required by paragraph (a) ofthis AD, accomplish the requirements of paragraphs (a)(2)(i) and (a)(2)(ii) of this AD, as applicable.

(i) If any corrosion or damage is detected, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate.

(ii) If any worn component is detected, within 600 flight hours after performing the inspection required by paragraph (a) of this AD, replace the component with a new or serviceable part in accordance with the service bulletin.

(b) Within 300 flight hours after accomplishing the inspection required by paragraph (a) of this AD, perform an operational inspection to ensure smooth operation of the spring strut of the forward door of the MLG, and relubricate the operating spring and sliding tube of the forward door A frame, in accordance with British Aerospace Service Bulletin ATP-32-84, Revision 1, dated September 26, 1997.

(1) Repeat the operational inspectionsthereafter at intervals not to exceed 300 flight hours, until the accumulation of 1,500 flight hours after the accomplishment of the inspection required by paragraph (a) of this AD.

(2) Following the accomplishment of all inspections required by paragraph (b)(1) of this AD, repeat the operational inspections and relubrication required by paragraph (b) of this AD at intervals not to exceed 1,500 flight hours.

(c) If any discrepancy is detected during any operational inspection and relubrication required by paragraph (b) of this AD, prior to further flight, replace any discrepant part with a new or serviceable part in accordance with a method approved by the Manager, International Branch, ANM-116.

(d) 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 MaintenanceInspector, 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.

(e) 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.

(f) Except as provided by paragraphs (a)(2)(i) and (c) of this AD, the actions shall be done in accordance with British Aerospace Service Bulletin ATP-32-84, Revision 1, dated September 26, 1997. 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 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.

(g) This amendment becomes effective on July 15, 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 April 6, 1998 (63 FR 16713). That action proposed to require a one-time inspection to detect corrosion, wear, or damage of the operating mechanism of the forward door of the main landing gear (MLG); operational inspections to ensure smooth operation of the MLG operating mechanism; and follow-on actions.

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, that it will take approximately 8 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $4,800, or $480 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.

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: