AD 96-05-07 Airworthiness Directives; Boeing Model 757 Series Airplanes Equipped with Pratt & Whitney Engines

Models named: 757 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 757 series airplanes equipped with Pratt & Whitney engines, certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (f) 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.

Required as indicated, unless accomplished previously. Note 2: Inspections accomplished prior to the effective date of this amendment in accordance with the procedures described in Boeing Service Bulletin 757-54A0019, Revision 4, dated May 27, 1993; Revision 3, dated March 26, 1992; or Revision 2, dated October 11, 1989; are considered acceptable for compliance with the applicable inspection specified in this amendment. To prevent cracking of the midspar fuse pins, which may lead to separation of the strut and engine from the wing of the airplane, accomplish the following: (a) For airplanes equipped with straight fuse pins, part number (P/N) 311N5067-1: Prior to the accumulation of 3,800 total flight cycles on the straight fuse pin, perform an eddy current inspection to detect cracking in the straight fuse pins, in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to [[Page 9601]] exceed 1,000 flight cycles on the straight fuse pin. (2) If any cracking is detected, prior to further flight, accomplish the requirements of either paragraph (a)(2)(i) or (a)(2)(ii) of this AD. (i) Replace the cracked straight fuse pin with a new straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 3,800 total flight cycles on that newly installed straight fuse pin, perform an eddy current inspection to detect cracking in that straight fuse pin, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on that newly installed straight fuse pin. Or (ii) Replace the cracked straight fuse pin with a new 15-5PH fuse pin, P/N 311N5217-1. Prior to the accumulation of 14,000 total flight cycles on that newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in that newly installed 15-5PH fuse pin, in accordance with the procedures described in the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin. (b) For airplanes equipped with refinished straight fuse pins, P/N 311N5067-1: Prior to the accumulation of 1,000 total flight cycles on the refinished straight fuse pin, perform an eddy current inspection to detect cracking in the refinished straight fuse pins, in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on the refinished straight fuse pin. (2) If any cracking is detected, prior to further flight, accomplish the requirements of either paragraph (b)(2)(i), (b)(2)(ii), or (b)(2)(iii) of this AD, in accordance with the service bulletin. (i) Replace the cracked refinished straight fuse pin with a crack-free refinished straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 1,000 total flight cycles on that newly installed refinished straight fuse pin, perform an eddy current inspection to detect cracking in that newly installed refinished straight fuse pin, in accordance with the procedures described in the service bulletin. Repeat this inspection thereafter at intervals not to exceed 1,000 flight cycles on the newly installed refinished straight fuse pin. Or (ii) Replace the cracked refinished straight fuse pin with a new straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 3,800 total flight cycles on that newly installed straight fuse pin, perform an eddy current inspection to detect cracking in that newly installed straight fuse pin, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on that newly installed straight fuse pin. Or (iii) Replace the cracked refinished straight fuse pin with a new 15-5PH fuse pin, P/N 311N5217-1. Prior to the accumulation of 14,000 total flight cycles on that newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in that newly installed 15-5PH pin, in accordance with the procedures described in the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin. (c) For airplanes equipped with bulkhead fuse pins, P/N 311N5211-1: Within 3,000 flight cycles after the effective date of this AD, replace the bulkhead fuse pins with 15-5PH fuse pins, P/N 311N5217-1, in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994, and accomplish the requirements of paragraph (d) of this AD. (d) For airplanes equipped with 15-5PH fuse pins: Prior to the accumulation of 14,000 total flight cycles on the 15-5PH fuse pins, perform an eddy current inspection to detect cracking in those 15- 5PH fuse pins, in accordance with the procedures described in Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on the 15-5PH fuse pin. (2) If any cracking is detected, accomplish the requirements of both paragraphs (d)(2)(i) and (d)(2)(ii) of this AD. (i) Prior to further flight, replace any cracked 15-5PH fuse pin with a new 15-5PH fuse pin, P/N 311N5217-1, in accordance with the procedures described in the service bulletin. And (ii) Prior to the accumulation of 14,000 total flight cycles on that newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in that newly installed 15-5PH fuse pin, in accordance with the procedures described in the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin. (e) Fuse pins must be of the same type on the same strut. For example, a steel fuse pin having P/N 311N5067-1 may not be installed on the same strut that has a corrosion-resistant steel (CRES) fuse pin having P/N 311N5217-1 installed on that strut. However, fuse pins on one strut may differ from those on another strut, provided the fuse pins are not of mixed types on the same strut. (f) 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, Seattle Aircraft Certification Office (ACO), 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, Seattle ACO. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (g) 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. (h) The inspections and replacements shall be done in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. 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. (i) This amendment becomes effective on April 10, 1996. Issued in Renton, Washington, on March 1, 1996. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 96-5369 Filed 3-8-96; 8:45 am] BILLING CODE 4910-13-U