AD 2000-03-04 Airworthiness Directives; General Electric Company CF6-80C2 Series Turbofan Engines

General Electric Company (GE) CF6-80C2 series turbofan engines, with fan mid shafts, part number (P/N) 9326M74P04 or P/N 9326M74P05, installed. These engines are installed on but not limited to Airbus Industrie A300 and A310 series, Boeing 747 and 767 series, and McDonnell Douglas MD-11 series aircraft. Note 1: This airworthiness directive (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 request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To prevent fan mid shaft failure, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: (a) Remove from service affected fan mid shafts and replace with a serviceable part, as follows: Note 2: GE CF6-80C2 Service Bulletin (SB) No. 72-958, dated December 10, 1998, contains information on this subject. (1) For fan mid shafts that have accumulated 9,000 or more cycles-since-new (CSN) on the effective date of this AD, remove from service within 3,500 cycles-in-service (CIS) after the effective date of this AD, or prior to accumulating 15,000 CSN, whichever occurs first. (2) For fan mid shafts that have accumulated 1,800 CSN or more, but less than 9,000 CSN on the effective date of this AD, remove from service within 5,000 CIS after the effective date of this AD, or prior to accumulating to 12,500 CSN, whichever occurs first. (3) For fan mid shafts that have accumulated less than 1,800 CSN on the effective date of this AD, remove from service prior to accumulating 6,800 CSN. Note 3: GE CF6-80C2 SB 72-750, Revision 2, dated September 4, 1998, contains information on reworking fan mid shafts that results in changing the P/N. After that rework, this AD would not apply to engines containing the reworked fan mid shaft. New Life Limits (b) Except for the provisions of paragraph (a) of this AD, no fan mid shafts, P/N 9326M74P04 or 9326M74P05, may remain in service beyond 6,800 CSN. Alternate Method of Compliance (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, Engine Certification Office (ECO). Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO. Note 4: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO. Ferry Flights (d) 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. (e) This amendment becomes effective on April 10, 2000. Issued in Burlington, Massachusetts, on February 2, 2000. David A. Downey, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 00-2988 Filed 2-9-00; 8:45 am] BILLING CODE 4910-13-U