AD 97-25-13

This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace BAe Model ATP airplanes and all Model HS 748 series airplanes, that requires inspection of the main hydraulic accumulator for corrosion, and corrective actions, if necessary. 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 detect and correct such corrosion, which could result in loss of certain hydraulic system functions, including nose wheel steering, hydraulic lowering of the landing gear, and main wheel brakes, which are essential for safe operation of the airplane.

Final rule

97-25-13 BRITISH AEROSPACE REGIONAL AIRCRAFT [Formerly Jetstream Aircraft Limited, British Aerospace (Commercial Aircraft) Limited]: Amendment 39-10237. Docket 97-NM-104-AD.
Applicability: BAe Model ATP airplanes having constructor s numbers 2002 through 2063 inclusive; and all Model HS 748 series airplanes; 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 (b) 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 detect and correct corrosion of the cylinder tube of the main hydraulic accumulator, which could result in loss of certain hydraulic system functions that are essential for safe operation of the airplane, accomplish the following:

(a) Within 30 days after the effective date of this AD, perform an inspection of the main hydraulic accumulator for corrosion, in accordance with British Aerospace Service Bulletin ATP-29-15, or HS748-29-49, both dated February 25, 1997; as applicable. If any discrepancy is found, prior to further flight, accomplish the applicable corrective actions specified in the service bulletins.

(b) 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 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.

(c) 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.

(d) The actions shall be done in accordance with British Aerospace Service Bulletin ATP-29-15, dated February 25, 1997, and British Aerospace Service Bulletin HS748-29-49, dated February 25, 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 obtainedfrom 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.

NOTE 3: The subject of this AD is addressed in British airworthiness directives 004-02-97, dated February 25, 1997, and 005-02-97, dated February 7, 1997.

(e) This amendment becomes effective on January 14, 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 and all Model HS 748 series airplanes was published in the Federal Register on August 20, 1997 (62 FR 44244). That action proposed to require inspection of the main hydraulic accumulator for corrosion, and corrective actions, if necessary.

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 British Aerospace BAe Model ATP airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplaneto 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 $600, or $60 per airplane.

Currently, there are no British Aerospace Model HS 748 series airplanes on the U.S. Register. However, should an affected airplane be imported and placed on the U.S. Register in the future, it would take approximately 1 work hour per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AD would be $60 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: