AD 95-08-03 Airworthiness Directives; General Electric Company CF6 Series Turbofan Engines

General Electric Company (GE) CF6-45/50 series turbofan engines installed on but not limited to Airbus A300 series, Boeing 747 series, and McDonnell Douglas DC-10 series aircraft. Note: This 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 use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any engine from the applicability of this AD.

Required as indicated, unless accomplished previously. To prevent a low cycle fatigue (LCF) failure of the high pressure turbine rotor (HPTR) stage 2 disk, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: (a) Remove from service HPTR stage 2 disks Part Numbers (P/N) 1474M49P04, 1474M49P05, 1474M49P06, 9045M35P15, 9045M35P17, and 9045M35P18, in accordance with the following: (1) For disks that have accumulated less than 3,500 cycles since new (CSN) on the effective date of this airworthiness directive (AD), remove disk from service prior to accumulating 7,080 CSN. (2) For disks that have accumulated 3,500 CSN or more, but less than 7,080 CSN on the effective date of this AD, remove disk from service prior to accumulating 7,080 CSN, or prior to accumulating 3,100 cycles in service (CIS) after the effective date of this AD, whichever occurs later, but not to exceed 9,700 CSN. (3) For disks which have accumulated 7,080 CSN or more on the effective date of this AD, remove disk from service at the next piece-part exposure, but not to exceed 9,700 CSN. (b) Remove from service HPTR stage 2 disks P/N 9264M58P01, 9264M58P02, and 9264M58P03 prior to accumulating 7,080 CSN. (c) This AD establishes the following new LCF retirement lives which will be published in Chapter 5 of the CF6-50 Engine Task Numbered Shop Manual, GEK 50481: 7,080 cycles for HPTR stage 2 disk P/N 1474M49P04, 1474M49P05, 1474M49P06, 9045M35P15, 9045M35P17, 9045M35P18, 9264M58P01, 9264M58P02, and 9264M58P03. (d) GE CF6-50 Service Bulletin (SB) No. 72-1069, dated September 12, 1994, describes an FAA-approved rework procedure for the affected disks. Accomplishment of this rework increases the FAA- approved LCF retirement life to 8,750 or 9,700 cycles, depending on the CSN of the disk when the rework is performed. (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 service bulletin: [[Page 18542]] ------------------------------------------------------------------------ Document No. Pages Date ------------------------------------------------------------------------ GE CF6-50 SB No. 72-1069................ 1-18 Sept. 12, 1994. 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 General Electric Aircraft Engines, CF6 Distribution Clerk, Room 132, 111 Merchant Street, Cincinnati, OH 45246. 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. (g) This amendment becomes effective on June 12, 1995. Issued in Burlington, Massachusetts, on March 31, 1995. James C. Jones, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 95-8712 Filed 4-11-95; 8:45 am] BILLING CODE 4910-13-U