AD 92-21-06

92-21-06 GARRETT ENGINE DIVISION, A DIVISION OF THE ALLIED SIGNAL AEROSPACE COMPANY: Amendment 39-8386. Applicability: Garrett Engine Division Model TFE731-2, -3, -3A, -3AR, and -3R turbofan engines assembled with Part Number (P/N) 3072068-X, 3072544-X, 3073015-X, or 3073115-X low pressure turbine (LPT) rotor disks identified by serial number listed in Allied-Signal Aerospace Company, Garrett Engine Division, Alert Service Bulletin (ASB) No. TFE731-A72-3474, dated April 3, 1992, installed on but not limited to Avions Marcel Dassault Falcon 10, 50, and 100, AiResearch Aviation Company 731 Jetstar, Lockheed 1329-25 (Jetstar II), Israel Aircraft Industries Ltd. 1124 Series (Westwind) and 1125 Westwind Astra, British Aerospace DH/HS/BH 125 Series, Learjet 31 (M31), 35, 36, and 55 Series, and Sabreliner NA265-65 (Sabreliner 65 and 65A Series) aircraft. Compliance: Required as indicated, unless accomplished previously. To prevent an uncontained engine failure, accomplish the following: (a) Remove affected third stage LPT rotor disks in accordance with the Accomplishment Instructions of Allied-Signal Aerospace Company, Garrett Engine Division, ASB No. TFE731-A72-3474, dated April 3, 1992, at the next access to the turbine rotor assembly or before accumulating 100 hours time in service after the effective date of this AD, whichever occurs first, and replace with a serviceable disk. (b) For the purpose of this AD, access to the turbine assembly is defined as whenever the low pressure turbine module is separated from the engine. (c) 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, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles Aircraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Los Angeles Aircraft Certification Office. (d) 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. (e) The removal and replacement of the LPT rotor disk shall be done in accordance with the following Allied-Signal Aerospace Company, Garrett Engine Division, Alert Service Bulletin:

Document No. Page No. Date No. TFE731-A72-3474 Total pages: 8 1-8 April 3, 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 Garrett General Aviation Services Division, Distribution Center, 1944 East Sky Harbor Circle, Phoenix, Arizona 85034, telephone (602) 365-2548. This information may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, Massachusetts; or at the Office of the Federal Register, 800 North Capitol Street NW., Suite 700, Washington, DC. (f) This amendment becomes effective on November 27, 1992.