AD 85-04-51

85-04-51 GARRETT TURBINE ENGINE COMPANY (GTEC) (formerly AiResearch Manufacturing Company of Arizona): Amendment 39-5061. Applicable to all model ATF3-6-2C turbofan engines with exhaust deflector liner and seal assembly, Garrett Part Numbers 3001313-10 through -14, and not incorporating the bolted flange system specified in paragraph (d) of this AD.

Compliance is required as indicated unless already accomplished.

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

(a) Within the next 25 operational hours after the effective date of this AD, visually inspect the stationary seal/sixth stage low pressure turbine rotor assembly area of all affected engines for evidence of seal/rotor contact and/or seal looseness as specified in section 2.A., "ACCOMPLISHMENT INSTRUCTIONS" of GTEC SB ATF3-A72-6113, dated February 25, 1985, or equivalent approved by the Manager, Western Aircraft Certification Office.

(b) Prior to the accumulation ofan additional 75 hours in service after accomplishing the inspection in paragraph (a) above, or within 25 operational hours after the effective date of this AD, whichever comes later, and at intervals not to exceed 75 operational hours thereafter, visually inspect the stationary seal/sixth stage low pressure turbine rotor assembly area of all affected 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 ATF3-6-2C Light Maintenance Manual Report No. 72-00-52 Revision 7, dated January 31, 1985; Temporary Revision No. 72-132, 72-00-00, Inspection dated February 25, 1985; Temporary Revision No. 72-133, 72-00-00, Inspection, dated February 25, 1985; Temporary Revision No. 72-135, 72-00-00, Trouble Shooting, dated February 25, 1985; Temporary Revision No. 72-136, 72-00-00, Trouble Shooting, dated February 25, 1985.

NOTE: Periodic measurements of the engine interstage turbine temperature (ITT) are required to be recorded in accordance with an FAA approved revision to the limitations section of the flight manual of the airplane. ITT differences outside airplane flight manual acceptable limits required inspection of the stationary seal/sixth stage low pressure turbine rotor assembly area prior to next flight.

(c) Engines with unsuccessful inspection results found during the accomplishment of paragraphs (a) or (b) above are to be disassembled as required to inspect, modify, or replace exhaust deflector liner and seal assembly and sixth stage turbine rotor assembly prior to further flight.

(d) Upon removal of the sixth stage low pressure turbine rotor assembly from an affected engine for any reason or within 500 operational hours after the effective date of this AD, whichever comes first, incorporate the new exhaust deflector liner and seal assembly bolted flangesystem as specified in Section 2.A., "ACCOMPLISHMENT INSTRUCTIONS" of GTEC SB ATF3-72-6114 dated February 25, 1985, or equivalent approved by the Manager, Western Aircraft Certification Office.

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

Upon request, an equivalent means of 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 persons 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 the Office of the Regional Counsel, New England Region, FAA, 12 New England Executive Park, Burlington, Massachusetts 01803, weekdays, except Federal holidays, between 8:00 a.m. and 4:30 p.m.

This amendment becomes effective June 24, 1985, to all persons except those persons to whom it was made immediately effective by telegraphic AD T85-04-51, issued March 1, 1985, which contained this amendment.