AD 84-20-51 ACTIVE

84-20-51 GARRETT TURBINE ENGINE COMPANY (GTEC) (formerly AiResearch Manufacturing Company of Arizona): Amendment 39-4965. Applicable to all engine models ATF3-6-4C, -6A-3C, and -6A-4C with exhaust deflector liner and seal assembly, Garrett part number (P/N) 3001313-11 through -14, installed.

Compliance required as indicated unless already accomplished.

To prevent the possibility of an uncontained engine failure, accomplish the following:

A. Prior to the accumulation of an additional 5 hours in service, after the effective date of this AD, and at intervals not to exceed 25 operational hours thereafter, until incorporation of the exhaust deflector liner and seal assembly bolted flange system as specified in Section 2.A., "Accomplishment Instructions," of GTEC SB ATF3-72-6092, dated May 25, 1984, or equivalent approved by the Manager, Western Aircraft Certification Office, visually inspect the stationary seal/sixth stage low pressure turbine rotor assembly area of allaffected engines for evidence of seal/rotor contact and/or seal looseness as specified in the following GTEC Light Maintenance Manual Revisions, or equivalent approved by the Manager, Western Aircraft Certification Office:

ENGINE MODEL
MANUAL REFERENCE
ATF3-6-4C
Light Maintenance Manual Report No. 72-00-52, Revision 6 dated November 15, 1983; Temporary Revision No. 72-88, 72-00-00, Trouble Shooting dated April 16, 1984; and Temporary Revision No. 72-89, 72-00-00, Trouble Shooting dated April 16, 1984.
ATF3-6A-3C
Light Maintenance Manual Report No. 72-03-32, Revision 3 dated November 15, 1983; Temporary Revision No. 72-43, 72-00-00, Trouble Shooting dated April 16, 1984; and Temporary Revision No. 72-44, 72-00-00, Trouble Shooting dated April 16, 1984.
ATF3-6A-4C
Light Maintenance Manual Report No. 72-03-42, Revision 4 dated November 15, 1983; Temporary Revision No. 72-44, 72-00-00, Trouble Shooting dated April 16, 1984; and Temporary Revision No. 72-45, 72-00-00, TroubleShooting dated April 16, 1984.

B. Engines with unsuccessful inspection results found during the accomplishment of paragraph A above are to be disassembled as required to modify the exhaust deflector liner and seal assembly and to inspect the sixth stage turbine rotor assembly.

C. Upon removal of the sixth stage low pressure turbine rotor assembly from an affected engine for any reason or within 200 operating hours after the effective date of this AD or prior to April 15, 1985, whichever comes first, incorporate the new exhaust deflector liner and seal assembly bolted flange system as specified in Section 2.A., "Accomplishment Instructions," of GTEC SB ATF3-72-6092, dated May 25, 1984, or equivalent approved by the Manager, Western Aircraft Certification Office.

Aircraft may be ferried in accordance with the provisions of Federal Aviation Regulations (FARs) 21.197 and 21.199 to a base where the AD can be accomplished.

Upon request of an operator, an equivalent meansof compliance with the requirements of this AD may be approved by the Manager, Western Aircraft Certification Office, Northwest Mountain Region, P.O. Box 92007, Worldway Postal Center, Los Angeles, California 90009.

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 person affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Garrett Turbine Engine Company, P.O. Box 5217, Phoenix, Arizona 85010; telephone (602) 231-1000. These documents also may be examined at Office of the Regional Counsel, New England Region, FAA, 12 New England Executive Park, Burlington, Massachusetts 01803.

This amendment supersedes Amendment 39-4900 (49 FR 35614), AD 84-11-51.

This amendment becomes effective December 26, 1984, to all persons except those persons to whom it was made immediately effective by telegraphic AD T84-20-51, issued October 4, 1984.