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/TFE731/16 HP Turbine Rotor Disc P/N 3072316-2/-3 and P/N 3073110-1/-2 5/89 DM Applicability: TFE 731-3 series engines fitted with HP turbine rotor disc whose serial numbers are listed in the Requirement Document. Requirement: Remove from service and inspect specific serial numbered HP turbine rotor disc P/N 3072316-2/-3 and P/N 3073110-1/-2 in accordance with Allied Signal Aerospace (Garrett) Service Bulletin TFE 731-A72-3388. Compliance: Prior to achieving 150 operating cycles after 29 March 1989. Background: A recent engine inflight shutdown was caused by the uncontained separation of an HP turbine rotor disc. Investigation determined that disc fracture occurred due to low cycle fatigue from an inclusion of foreign material within the disc. This Directive is issued to remove from service and inspect suspect HP turbine discs.