AD 75-22-11

75-22-11 GENERAL ELECTRIC: Amendment 39-2398. Applies to Models CF6-6D and CF6-6D1 Turbofan Engines. Compliance required as indicated.

To prevent possible disintegration of the high pressure turbine thermal shield accomplish the following:

(a) Within the next 400 operating cycles after the effective date of this Airworthiness Directive, unless already accomplished, and every 400 cycles thereafter, borescope inspect the high pressure turbine thermal shield on all CF6-6D and CF6-6D1 engines except those noted in paragraph (b) below in accordance with the instructions of General Electric Service Bulletin (CF6-6) 72-603 dated October 1, 1975 or subsequent FAA Approved revision.

(b) Inspection is not required:

(1) On engines containing thermal shields replaced or modified in accordance with General Electric Service Bulletin (CF6-6) 72-442, dated October 8, 1973, Revision 1 or subsequent FAA Approved revision, or General Electric Service Bulletin (CF6-6) 72-502 dated October 23, 1974 or subsequent FAA Approved revision.

(2) On engines incorporating thermal shields, General Electric part number 9687M67P08, assembly number 9687M67G12; part number 9687M67P09, assembly number 9687M67G13; part number 9687M67P12, assembly number 9687M67G16; or part number 9687M67P17, assembly number 9687M67G21.

(c) For the purposes of this Airworthiness Directive, the definition of a "cycle" is the definition appearing in the General Electric CF6-6 Shop Manual GEK 9266, Section 72-00-00, Page 301 dated August 1, 1975 or subsequent FAA Approved revision.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to General Electric Company, Cincinnati, Ohio 45215. These documents may also be examined at the FAA Great Lakes Region, 2300 E. Devon Avenue, Des Plaines, Illinois 60018 and at FAA headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and at the Great Lakes Region.

This amendment becomes effective October 28, 1975.