93-13-10 GENERAL ELECTRIC COMPANY: Amendment 39-8623. Docket 91-ANE-54.
Applicability: General Electric Company (GE) CF6-45/-50 series turbofan engines installed on but not limited to McDonnell Douglas DC-10, Airbus A300, and Boeing 747 series aircraft.
Compliance: Required as indicated, unless accomplished previously.
To prevent engine stall, aborted takeoff, or inflight engine shutdown, accomplish the following:
(a) Perform a visual and fluorescent penetrant inspection (FPI) for cracks, and perform a mechanical gage or ultrasonic thickness measurement of the stage 12 compressor disk web-to-rim transition area of the stage 11-13 compressor spool in accordance with GE CF6-50 Service Bulletin (SB) No. 72-1006, Revision 1, dated November 14, 1991, as follows:
(1) For those stage 11-13 compressor spools listed in Table 1 of GE CF6-50 SB No. 72-1006, Revision 1, dated November 14, 1991, at the next engine shop visit, within 3,500 cycles in service after the effective date of this AD, or by December 31, 1997, whichever occurs first.
(2) For all other stage 11-13 compressor spools, at the next piece-part exposure, or by December 31, 1997, whichever occurs first.
(b) For stage 11-13 compressor spools that have cracked stage 12 compressor disk web-to-rim transition areas, or that have stage 12 compressor disk web-to-rim transition areas measuring less than 0.070 inches thick, remove from service prior to further flight, and replace with a serviceable stage 11-13 compressor spool.
(c) For stage 11-13 compressor spools that have stage 12 compressor disk web-to- rim transition areas with a minimum thickness greater than or equal to 0.070 inches but less than 0.074 inches, reidentify the stage 11-13 compressor spool with a new part number in accordance with GE CF6-50 SB No. 72-1006, Revision 1, dated November 14, 1991. The reidentified stage 11-13 compressor spool has a life limit of 16,000 cycles since new (CSN).
(d) For stage 11-13 compressor spools that have stage 12 compressor disk web-to- rim transition areas with a minimum thickness of 0.074 or more inches, mark "SB 72-1006" next to the part number and serial number on the forward spacer arm in accordance with GE CF6-50 SB No. 72-1006, Revision 1, dated November 14, 1991. The life limit of this stage 11-13 compressor spool remains at 19,000 CSN.
(e) For the purpose of this AD, an engine shop visit is defined as the induction of an engine into a shop for maintenance involving the separation of a major module.
(f) 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 withthis airworthiness directive, if any, may be obtained from the Engine Certification Office.
(g) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.
(h) The inspection, and replacement, if necessary, shall be done in accordance with the following service bulletin:
Document No.
Pages
Revision
Date
GE CF6-50 SB
No. 72-1006
1-30
1
November 14, 1991
Total Pages: 30
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.
(i) This amendment becomes effective on September 21, 1993.