COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/56 Main Landing Gear Shock Strut Outer Cylinder - Inspection 4/68 Applicability: All models. Requirement: Inspect for cracking, all chrome plated main landing gear outer cylinder aft trunnion extensions which have been overhauled in a manner other than specifically described by Boeing 727 Overhaul Manual Section 32/12/1. Compliance: Forthwith.