COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series AD/TFE731/10 No. 1 Bearing - Replacement 3/86 TX Applicability: TFE 731-2, -3, -5 Series with Serial Nos. as listed in the Requirement Document. Requirement: Replace suspect defective Number 1 bearings of affected engines. G.T.E.C. Alert S.B. TFE 731-A72-3296 refers; or AD/AIR-T/51. Compliance: Unless already accomplished, within 25 hours time in service after 23 November 1984. Background: This Directive is issued to remove from service defective No. 1 bearings. Following a reported failure, it has been established that defective bearings have been fitted to some engines. These engines have been identified in SB TFE 731-A72-3296. Defective bearings have insufficient roller end clearance which results in skidding and subsequent failure.