AD 90-22-02

90-22-02 PRATT & WHITNEY: Amendment 39-6783. Docket No. 90-ANE-27. Applicability: Pratt & Whitney (PW) PW4050, PW4052, PW4056, PW4060, PW4060A, PW4152, PW4156, PW4158, and PW4460 turbofan engines installed on, but not limited to, Boeing 747, Boeing 767, Airbus A300, and Airbus A310 type aircraft. Compliance: Required as indicated, unless previously accomplished. To prevent a low pressure turbine (LPT) shaft failure that can cause a total loss of thrust and inflight shutdown, accomplish the following: (a) Conduct a one-time eddy current inspection of the inner diameter bore surface of the LPT shaft, between 23 and 44 inches forward of the aft end, in accordance with the Accomplishment Instructions of PW Alert Service Bulletin (ASB) No. PW4ENG 72-328, dated September 28, 1990, for LPT shafts installed on engines identified by serial number in Table 2 of the ASB, prior to October 31, 1990. (b) Conduct a one-time eddy current inspection of the inner diameter bore surface of the LPT shaft, between 23 and 44 inches forward of the aft end, in accordance with the Accomplishment Instructions of PW ASB No. PW4ENG 72-328, dated September 28, 1990, for LPT shafts installed in engines identified by serial number as follows, excluding those shafts subject to the requirements of (a) above, prior to December 31, 1990.

Engine Model Engine Serial Number PW4050 P724201 through P724208, inclusive PW4052 P723701 through P723706, inclusive PW4056 P717501 through P717696, inclusive, except P717692 PW4060 P724101 through P724164, inclusive PW4060A P724501 through P724506, inclusive PW4152 P717701 through P717775, inclusive PW4156 P717201 through P717205, inclusive PW4158 P724001 through P724076, inclusive PW4460 P723801 through P723828, inclusive

(c) Remove from service, prior to further flight, LPT shafts found cracked during inspections conducted in accordance with (a) or (b) above. (d) LPT shafts which have been previously inspected in accordance with PW Special Instruction 70F-90, dated September 14, 1990, are in compliance with this AD. (e) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished. (f) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance times specified in this AD may be approved by the Manager, Engine Certification Office, ANE-140, Engine & Propeller Directorate, Aircraft Certification Service, FAA, 12 New England Executive Park, Burlington, Massachusetts 01803. The eddy current inspections of the LPT shafts shall be done in accordance with the following PW document:

Document Number Page Number Issue/Revision Date PW ASB PW4ENG 72-328 All Original 9/28/90

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, P. O. Box 611, Middletown, Connecticut 06457. Copies may be inspected at the Regional Rules Docket, Office of the Assistant Chief Counsel, FAA, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts 01803, or at the Office of the Federal Register, 1100 L Street, NW, Room 8301, Washington, DC 20591. This amendment (39-6783, AD 90-22-02) becomes effective on October 18, 1990.