96-17-11: Low pressure turbine (LPT) vane

96-17-11 Pratt & Whitney: Amendment 39-9721. Docket 94-ANE-51. Applicability: Pratt & Whitney (PW) JT9D-7R4 series turbofan engines, installed on but not limited to Airbus A300 and A310 series, and Boeing 747 and 767 series aircraft. Note: This airworthiness directive (AD) applies to each engine 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 engines 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 (e) 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 prevent low pressure turbine (LPT) vane failures, which can result in uncontained engine failure, fire, and possible damage to the aircraft, accomplish the following, accomplish the following: (a) Remove 5th stage LPT vane cluster segments that incorporate electro-discharge machined (EDM) slots, Part Numbers (P/N) 787885 or 787885-001, and replace with the cast pocket vane configuration, P/N 796985, 795175, 796985-001, 808875, 811985, or 811985-001, at the next shop visit, but not later than 5,000 cycles in service (CIS) after the effective date of this AD, in accordance with PW Alert Service Bulletin (ASB) No. JT9D-7R4-72-480, dated April 20, 1993. Note: Pratt & Whitney SB No. JT9D-7R4-72-473, Revision 2, dated February 8, 1993, may be used to segregate EDM slot from cast pocket 5th stage LPT vane clusters sharing the same P/N 787885 and 787885-001. (b) For LPT modules that previously have had the 3rd,4th, or 5th stage vane retention hardware disassembled for any reason perform paragraph (b)(1), (b)(2), or (b)(3) of this AD at the next shop visit, but not later than 5,000 CIS after the effective date of this AD, accomplish one of the following. Do not use uncured anti-gallant compound on the bolts or nuts: (1) Install new 3rd, 4th, and 5th stage LPT vane bolts and nuts, in accordance with PW ASB No. JT9D-7R4-72-481, dated April 20, 1993; or (2) Install new 3rd, 4th, and 5th stage LPT vane bolts and nuts, and install heat shield assemblies and air sealing ring stop assemblies in accordance with PW SB No. JT9D-7R4-72- 484, Revision 1, dated October 9, 1993; or (3) Install new 3rd, 4th, and 5th stage LPT vane bolts and nuts, and install heat shield assemblies and air sealing ring stop assemblies in accordance with PW SB No. JT9D-7R4-72- 484, Revision 1, dated October 9, 1993, and PW SB No. JT9D-7R4-72-488, Revision 1, dated November 20, 1993. (c) For LPT modules that have never had the 3rd, 4th, or 5th stage vane retention hardware disassembled, perform paragraph (b)(1), (b)(2), or (b)(3) of this AD at the first LPT module disassembly. Do not use uncured anti-gallant compound on the bolts or nuts. (d) For the purpose of this AD, a shop visit is defined as the induction of an engine into a maintenance facility for the purpose of either: (1) Separation of pairs of major mating engine flanges; or (2) The removal of an engine disk, hub, or spool. (e) 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, Engine Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. Note: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any,may be obtained from the Engine Certification Office. (f) 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 aircraft to a location where the requirements of this AD can be accomplished. (g) The actions required by this AD shall be done in accordance with the following PW service documents: Document No Pages Revision Date SB No. JT9D-7R4 -72-473 1 2 February 8, 1993 2-5 Original November 11, 1992 6, 7 2 February 8, 1993 8 Original November 11, 1992 9 1 December 16, 1992 10, 11 2 February 8, 1993 Total Pages: 12. ASB No. JT9D-7R4 -72-480 1-13 Original April 20, 1993 Total Pages: 13. ASB No. JT9D-7R4 -72-481 1-11 Original April 20, 1993 Total Pages: 11. SB No. JT9D-7R4 -72-484 1 1 October 9, 1993 2-8 Original August 2, 1993 9 1 October 9, 1993 10-16 Original August 2, 199317 1 October 9, 1993 18-44 Original August 2, 1993 Total Pages: 44. SB No. JT9D-7R4 -72-488 1 1 November 20, 1993 2 Original October 7, 1993 3 1 November 20, 1993 4-17 Original October 7, 1993 18 1 November 20, 1993 Total Pages: 18. 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 Pratt & Whitney, Publications Department, Supervisor Technical Publications Distribution, M/S 132-30, 400 Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street NW., suite 700, Washington, DC. (h) This amendment becomes effective on November 18, 1996.