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93-06-05
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Blade Failure Category - Engine Applicability:
Pratt & Whitney (PW) JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15,
-17, and -17R turbofan engines except those engines containing fan exhaust
inner front duct segment assemblies that are installed in accordance with
PW Alert Service Bulletin (ASB) No. 6039, Revision 2, dated May 4, 1992,
or earlier revisions of PW ASB No. 6039, and either Compliance: Required as indicated, unless accomplished previously. To prevent third and fourth stage low pressure turbine (LPT) blade fractures that can result in an inflight engine shutdown, engine cowl release, or uncontained engine debris penetrating the aircraft, accomplish the following: (a) Conduct initial and repetitive inspections on installed third andfourth stage LPT blade sets, and remove and replace with serviceable blade sets, as necessary, in accordance with Part 1 of the Accomplishment Instructions of PW ASB No. 5913, Revision 5, dated August 10, 1992, as follows: (1) Initially inspect the blade shroud crossnotches of the third stage LPT blade set when specified in paragraphs (a)(1)(i) or (a)(1)(ii) of this AD, whichever occurs later. Engines that contain a third stage blade set that have third stage turbine blades that were installed per the requirements specified in PW Service Bulletin No. 5331, dated October 27, 1982, do not require the third stage blade set inspection. (i) Inspect within 6,000 cycles or 6,000 hours time in service, whichever occurs first, since new, since the last blade shroud crossnotch inspection specified in Section 72-53-12 of PW JT8D Engine Manual P/N 481672, or since last blade shroud crossnotch repair that was accomplished per the requirements specified in Section 72-53-12 of PW JT8D Engine Manual P/N 481672; or (ii) Inspect within 1,000 cycles or 1,000 hours time in service, whichever occurs first, after the effective date of this AD. (2) Initially inspect the blade shroud crossnotches of the fourth stage LPT blade set when specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD, whichever occurs later. Engines that contain fan exhaust inner front duct segment assemblies that were installed per the requirements of PW ASB No. 6039, Revision 2, dated May 4, 1992, or earlier revisions of PW ASB No. 6039, do not require the fourth stage blade set inspection. (i) Inspect within 6,000 cycles or 6,000 hours time in service, whichever occurs first, since new, since the last blade shroud crossnotch inspection specified Section 72-53-13 of PW JT8D Engine Manual P/N 481672, or since last blade shroud crossnotch repair that was accomplished per the requirements specified in Section 72-53-13 of PW JT8D Engine Manual P/N 481672; or (ii) Inspect within 1,000 cycles or 1,000 hours time in service, whichever occurs first, after the effective date of this AD. (3) Thereafter, reinspect the third and fourth stage LPT blade sets in accordance with the procedures and intervals specified in PW ASB No. 5913, Revision 5, dated August 10, 1992. (b) An alternative method of compliance or adjustment of the compliance times 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. (c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (d) The inspections, and removal, if necessary, of the third and fourth stage LPT blades shall be done in accordance with the following service document: Document No. Pages Issue Date PW ASB No. 5913
1 Revision 5 August 10, 1992 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, Technical Publications Department, M/S 132-30, 400 Main Street, East Hartford, Connecticut 06108. Copies may be inspected at the FAA, Office of Assistant Chief Counsel, New England Region, 12 New England Executive Park, Burlington, Massachusetts; or at the Office ofthe Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (e) This amendment becomes effective on July 7, 1993. FOR FURTHER INFORMATION CONTACT: John E. Golinski, Aerospace Engineer, Engine Certification Office, ANE-140,FAA, New England Region, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts 01803-5299, telephone (617) 273-7121; fax (617) 270-2412.
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