95-21-13: Servo Tab & Trim Tab Drive Brackets

95-21-13 BRITISH AEROSPACE REGIONAL AIRCRAFT LIMITED, AVRO INTERNATIONAL AEROSPACE DIVISION (Formerly British Aerospace, plc; British Aerospace Commercial Aircraft Limited): Amendment 39-9400. Docket 95-NM-189-AD. Applicability: All Model BAe 146 series airplanes; and all Model Avro 146-RJ series airplanes, all line numbers up to and including line number E3263; 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 use the authority provided in paragraph (b) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessaryto address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD. Compliance: Required as indicated, unless accomplished previously. To prevent the failure of the servo and trim tab drive brackets of the aileron due to cracking associated with corrosion, which could result in reduced controllability of the airplane, accomplish the following: (a) Within 14 days after the effective date of this AD, perform a detailed visual inspection to detect damaged or missing surface protective finish, corrosion, or cracking on the servo tab brackets and the trim tab drive brackets of the aileron (total of 6 brackets), in accordance with British Aerospace Service Bulletin S.B. 57-47, dated June 15, 1995 (for Model BAe 146 series airplanes), or British Aerospace Service Bulletin S.B. 57-48, dated June 30, 1995 (for Model Avro 146-RJ series airplanes), as applicable. (1) If no discrepancy is found, no further action is required by this AD. (2) If any discrepancy is found on the surface protection finish, but no corrosion or cracking is detected on any servo tab bracket or trim tab drive bracket, prior to further flight, reapply the intermediate (barrier) coat and the strippable polyurethane gloss top coat (aluminum colored), in accordance with the applicable service bulletin. (3) If any corrosion, but no cracking, is detected on the servo tab bracket or trim tab drive bracket, repeat the inspection thereafter at intervals not to exceed 50 landings. Prior to the accumulation of 500 landings after the initial inspection, remove corrosion and reapply the intermediate (barrier) coat and the strippable polyurethane gloss top coat (aluminum colored), in accordance with the applicable service bulletin.(4) If any cracking is detected on the servo tab drive bracket, prior to further flight, replace the cracked bracket with a new bracket, in accordance with the applicable service bulletin. After accomplishing the replacement, no further action is required by this AD for that servo tab bracket. (5) If any cracking is detected in only one flange of a single trim tab drive bracket and no other discrepancy is detected, repeat the inspection thereafter at intervals not to exceed 10 landings. Prior to the accumulation of 50 landings after the initial inspection, replace the cracked trim tab drive bracket with a new bracket, in accordance with the applicable service bulletin. After accomplishing the replacement, no further action is required by this AD for that trim tab drive bracket. (6) If any cracking is detected in the trim tab drive bracket and the crack has propagated through the flange or cracking exists in more than one flange of the bracket, prior to further flight, replace the cracked trim tab drive bracket with a new bracket, in accordance with the applicable service bulletin. After accomplishing the replacement, no further action is required by this AD for that trim tab drive bracket. (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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113. NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (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 S.B. 57-47, dated June 15, 1995, or British Aerospace Service Bulletin S.B. 57-48, dated June 30, 1995, 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 British Aerospace Holding, Inc., Avro International Aerospace Division, P.O. Box 16039, Dulles International Airport, Washington DC 20041-6039. 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. (e) This amendment becomes effective on November 2, 1995.