90-24-06: Thermocouple Lead Assemblies

90-24-06 GARRETT ENGINE DIVISION, ALLIED-SIGNAL, INC. (formerly Garrett Turbine Engine Co., GTEC, formerly AiResearch Manufacturing Company of Arizona): Amendment 39-6685. Docket No. 90-ANE-15. Applicability: Models TFE731-2, -2A, -3, -3A, -3AR, -3B, -3BR, -3R, -5, -5AR, and -5R turbofan engines equipped with thermocouple lead assemblies, part numbers (P/N) 3073950-1/-2/-7/-15, 3074175-1, and P/N 3073950-1 reworked to P/N 3077031-1/-2, installed in aircraft certificated in any category. Compliance: Required as indicated, unless already accomplished. To prevent overtemperature and damage of turbine components, accomplish the following: a. Remove from service and replace with a serviceable part thermocouple lead assemblies with serial numbers listed in Table 1, in Garrett Service Bulletin (SB) TFE731-A77-3020, dated April 27, 1990, within 25 operating hours in service after the effective date of this AD, in accordance with the accomplishment instructions of the above Garrett SB. Engines with thermocouple lead assemblies with serial numbers having a "T" suffix are excluded from the requirements of this AD. b. Test suspect lead assemblies in accordance with Accomplishment Instructions of Garrett SB TFE731-A77-3020, to determine if additional maintenance action is required before further operation of the engine in service. c. Remove from service engines that had suspect lead assemblies removed as required by paragraph a. of this AD, in which the removed lead assembly tested faulty, until the engine has been determined to be airworthy in accordance with the accomplishment instruction of the SB. d. 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. e. Upon submission of substantiating data by an owner or operator through a FAA Airworthiness Inspector, the Manager, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, Aircraft Certification Service, Federal Aviation Administration, 3229 East Spring Street, Long Beach, California 90806- 2425, may approve an equivalent means of compliance or an adjustment of the compliance schedule which provides an equivalent level of safety. The removal, replacement, and testing of certain thermocouple lead assemblies and the testing of certain engines shall be done in accordance with Garrett SB TFE731-A77-3020, dated April 27, 1990. 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 Garrett General Aviation Services Division, Distribution Center, 2340 East University, Phoenix, Arizona 85034. 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 (39-6685, AD 90-24-06) becomes effective on November 13, 1990.