AD 91-10-03 Airworthiness Directives; General Electric Company (GE) CF6-45 and CF6-50 Series Turbofan Engines

General Electric Company (GE) CF6-45 and CF6-50 series turbofan engines installed on, but not limited to, McDonnell Douglas DC-10 series, Boeing 747 series, and Airbus A300 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 high pressure compressor (HPC) rear shaft fracture, which could result in an inflight engine shutdown and an uncontained engine failure, accomplish the following: (a) Fluorescent penetrant inspect HPC rear shafts, Part Numbers (P/N) 9127M58P03, 9079M63P12, 9079M63P15, 9079M63P16, 9079M63P17, 9079M63P18, and 9079M63P19, in accordance with the Accomplishment Instructions of GE Service Bulletin (SB) No. 72-958, Revision 1, dated October 18, 1990, as follows: (1) For HPC rear shafts currently installed with hook bolts, P/N 9012M99G10, 9114M95G07, and 9114M95G10, inspect in accordance with the following schedule: (i) For shafts which have not been previously inspected and have 10,000 cycles since new (CSN) or greater on the effective date of this airworthiness directive (AD), inspect within the next 1,500 cycles in service (CIS) after the effective date of this AD. (ii) For shafts which have not been previously inspected and have less than 10,000 CSN on the effective date of this AD, inspect within the next 2,500 CIS from the effective date of this AD, or before accumulating 7,500 CSN, whichever occurs later. However, no shaft may exceed 11,500 CSN prior to inspection. (iii) For shafts that have been previously inspected and have 3,000 cycles since last inspection (CSLI) or less on the effective date of this AD, reinspect within 4,500 CSLI, or before accumulating 7,500 CSN, whichever occurs later. (iv) For shafts that have been previously inspected and have greater than 3,000 CSLI on the effective date of this AD, reinspect within the next 1,500 CIS from the effective date of this AD, or before accumulating 7,500 CSN, whichever occurs later. (v) Remove from service, HPC rear shaft hook bolts identified in (a)(1) of this AD, after any inspection performed in accordance with paragraph (a)(1) of this AD, and replace with new tapered turn- around bolts, P/N 1375M69P01 or VCD0016. (2) For HPC rear shafts installed with turn-around bolts, P/N 9249M54P01, or tapered turn-around bolts, P/N 1375M69P01 or [[Page 18731]] VCD0016, inspect in accordance with the following schedule: (i) For shafts which have not been previously inspected and have 6,500 CSN or greater on the effective date of this AD, inspect within the next 2,500 CIS after the effective date of this AD. (ii) For shafts which have not been previously inspected and have less than 6,500 CSN on the effective date of this AD, inspect prior to accumulating 9,000 CSN. (iii) For shafts that have been previously inspected and have 3,500 CSLI or less on the effective date of this AD, reinspect within 6,000 CSLI, or before accumulating 9,000 CSN, whichever occurs later. (iv) For shafts that have been previously inspected and have greater than 3,500 CSLI on the effective date of this AD, reinspect within the next 2,500 CIS from the effective date of this AD, or before accumulating 9,000 CSN, whichever occurs later. (v) Remove from service, HPC rear shaft turn-around bolts identified in paragraph (a)(2) of this AD, after any inspection performed in accordance with paragraph (a)(2) of this AD, and replace with new tapered turn-around bolts, P/N 1375M69P01 or VCD0016. Note: Information concerning the tapered turn-around bolt noted in paragraph (a) of this AD can be found in GE SB No. 72-877. (b) Remove from service, prior to further flight, any shafts found cracked at inspection. (c) Thereafter, for shafts which have been inspected in accordance with paragraph (a) of this AD, reinspect in accordance with the Accomplishment Instructions of GE SB No. 72-958, Revision 1, dated October 18, 1990, at intervals not to exceed 6,000 CSLI. (d) Compliance with paragraph (a) of AD 91-10-03 satisfies the corresponding requirements of paragraph (a) of this AD. (e) An alternative method of compliance or adjustment of the initial 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 AD, 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 document: ------------------------------------------------------------------------ Document No. Pages Revision Date ------------------------------------------------------------------------ GE SB No. 72-958........... 1-2 1........... Oct. 18, 1990. 3-6 Original.... Aug. 15, 1990. Total pages: 6. ------------------------------------------------------------------------ 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 as of June 17, 1991. Copies may be obtained from General Electric Company, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215. 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 April 28, 1995. Issued in Burlington, Massachusetts, on April 4, 1995. James C. Jones, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 95-9133 Filed 4-11-95; 11:45 am] BILLING CODE 4910-13-U