AD 97-09-02 Airworthiness Directives; CFM International CFM56-5C Series Turbofan Engines

CFM International (CFMI) CFM56-5C2/G, -5C3/G, and -5C4 series turbofan engines, installed on but not limited to Airbus A340 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 (h) 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 a low cycle fatigue (LCF) failure of the high pressure turbine rotor (HPTR) front shaft, HPTR front air seal, HPTR disk, booster spool, and low pressure turbine rotor (LPTR) stage 3 disk, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: (a) Remove from service HPTR front shafts, Part Numbers (P/N's) 1498M40P03, 1498M40P05, and 1498M40P06, prior to accumulating 8,400 cycles since new (CSN), and replace with a serviceable part. (b) Remove from service HPTR front air seals, P/N's 1523M34P02 and 1523M34P03, prior to accumulating 4,000 CSN, and replace with a serviceable part. (c) Remove from service HPTR disks, P/N 1498M43P04, prior to accumulating 6,200 CSN, and replace with a serviceable part. (d) Remove from service booster spools, P/N 337-005-210-0, prior to accumulating 13,000 CSN, and replace with a serviceable part. (e) Remove from service LPTR stage 3 disks, P/N's 337-001-602-0 and 337-001-605-0, prior to accumulating 7,000 CSN, and replace with a serviceable part. (f) This action establishes the new LCF retirement lives stated in paragraphs (a) through (e) of this AD, which are published in Chapter 05 of the CFM56-5C Engine Shop Manual, CFMI-TP.SM.8. (g) For the purpose of this AD, a ``serviceable part'' is one that has not exceeded its respective new life limit as set out in this AD. (h) 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 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office. (i) 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. (j) This amendment becomes effective on June 30, 1997. Issued in Burlington, Massachusetts, on April 22, 1997. Robert E. Guyotte, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 97-11298 Filed 4-30-97; 8:45 am] BILLING CODE 4910-13-U