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99-24-14 General Electric Company: Amendment 39-11438. Docket 99-NE-52-AD. Issued October 18, 1999.
Applicability: General Electric Company (GE) CF6-80E1A2 series turbofan engines, with stage 2 high pressure turbine (HPT) disks, part number (P/N) 1639M50P03, and HPT impeller spacers, P/N 1473M85P02, installed. These engines are installed on but not limited to Airbus Industrie A330 series airplanes.
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 (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repairon 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.
Compliance: Required as indicated, unless accomplished previously.
To prevent low cycle fatigue (LCF) cracking and failure of stage 2 HPT disks and impeller spacers, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: Stage 2 HPT Disks Drawdown Plan
(a) Remove from service stage 2 HPT disks, P/N 1639M50P03, and replace with serviceable parts, as follows:
Note 2: GE CF6-80E1A2 Service Bulletin (SB) 72-0169, dated July 22, 1999, describes the stage 2 HPT disk drawdown plan.
(1) For disks that have accumulated greater than or equal to 3,800 cycles-since-new (CSN) on the effective date of this AD, remove within 200 cycles-in-service (CIS) after the effective date of this AD, but not to exceed 6,400 CSN.
(2) For disks that have accumulated greater than or equal to 2,500 CSN on the effective date of this AD and less than 3,800 CSN on the effective date of this AD, remove from service prior to accumulating 4,000 CSN.
(3) For disks that have accumulated greater than or equal to 1,900 CSN on the effective date of this AD and less than 2,500 CSN on the effective date of this AD, remove from service within 1,500 CIS after the effective date of the AD.
(4) For disks that have accumulated less than 1,900 CSN on the effective date of this AD, remove prior to accumulating 3,400 CSN.
New, Stage 2 HPT Disk Lower Life Limit
(b) Except for the provisions of paragraph (d) of this AD, no stage 2 HPT disk, P/N 1639M50P03, may be installed with 3,400 or greater CSN.
New, Lower HPT Impeller Spacer Life Limit
(c) Remove from service HPT impeller spacers, P/N 1473M85P02, prior to accumulating 5,100 CSN. Except for the provisions of paragraph (d) of this AD, no HPT impeller spacer, P/N 1473M85P02, may be installed with 5,100 or greater CSN.
Note 3: GE CF6-80E1A2 SB 72-0169, dated July 22, 1999, describes an HPT impeller spacer drawdown plan that is not utilized in this AD.
Alternative Method of Compliance
(d) 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
(e) 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.
(f) This amendment becomes effective on December 18, 1999.
