COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes AD/AC/17A Landing Gear Truss Attach Angle - Inspection 12/67 Applicability: All models: S/Nos. 231 to 892 except 875. Document: Aero Commander SL No. 77A. Compliance: At intervals not exceeding 1000 hours' time in service.