COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AlliedSignal (Lycoming) Turbine Engines - T53 Series AD/T53/13 Improved Centrifugal Compressor Impeller - Introduction 1/86 Applicability: All T5313B engines. Document: 1. Lycoming SB No. 0042; or 2. FAA AD 75-01-05; or 3. AD/LYC-T/14. Compliance: Before 28 February 1975.