COMMONWEALTH OF AUSTRALIA CIVIL AVIATION ORDERS CIVIL AVIATION SAFETY AUTHORITY PART 105 SCHEDULE OF AIRWORTHINESS DIRECTIVES GULFSTREAM (GRUMMAN) G.159 SERIES AEROPLANES AD/G159/5 Amdt 2 APU Turbine Wheel - Inspection 11/7 1 Applicability: All models. Document: 1. Airesearch SB No. 49-1045; or 2. Grumman Customer Bulletin No. 180; or 3. FAA AD 65-9-3. Compliance: At intervals not exceeding 250 hours of APU operation or 500 APU starts, whichever occurs first.