COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/55 Amdt 1 Main Landing Gear Uplock and Downlock - Inspection and Modification 5/67 Applicability: All models. Document: Boeing SB No. 32-123, Rev. 4. Compliance: Forthwith.