AD 90-12-06

90-12-06 GENERAL ELECTRIC COMPANY: Amendment 39-6591. Docket No. 89-ANE-07.

Applicability: General Electric Company (GE) CF6-50/-45 turbofan engines installed on, but not limited to, McDonnell Douglas DC-10, Airbus A300, and Boeing B747 aircraft.

Compliance: Required at the next shop visit after the effective date of this AD, but not later than January 1, 1992, unless already accomplished.

To prevent uncontained low pressure turbine (LPT) failure due to a fire in the LPT rotor cavity, accomplish the following:

(a) Install the center vent tube extension assembly and associated hardware in accordance with GE CF6- 50 Series Service Bulletin (SB) 72-395, Revision 3, dated June 30, 1989.

NOTE: Shop visit for the purpose of this AD is defined as the induction of the engine into the shop for performance of maintenance.

(b) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished.

(c)Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance (schedule) times specified in this AD may be approved by the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803. The installation of the center vent tube extension assembly and associated hardware shall be done in accordance with GE CF6-50 Series SB 72-395, Revision 3, dated June 30, 1989, which incorporates the following list of effective pages:

Page Number Revision Number Date Pages 1 - 6 Revision 3 June 30, 1989 Page 7 Revision 1 April 29, 1977 Pages 8 - 26 Revision 3 June 30, 1989

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, Ohio 45246. Copies may be inspected at the Regional Rules Docket, Office of the Assistant Chief Counsel, Federal Aviation Administration, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts 01803, or at the Office of the Federal Register, 1100 L Street, NW, Room 8301, Washington, DC 20591.

This amendment (39-6591, AD 90-12-06) becomes effective on June 25, 1990.