COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/71 Outboard Aileron Tab Mast Fitting - Inspection and Modification Applicability: All models with S/Nos. as detailed in SB No. 57-137. Document: 1. Boeing SB No. 727-57-137, Rev. 2; or 2. FAA AD 75-20-09, Amdt. 39-2375. 11/75 Compliance: 1. Inspect: Initially within 500 hours time in service after 28 November 1975 unless already accomplished, and thereafter at intervals not exceeding 1500 hours time in service until modified by replacement of all blind rivets with bolts and nut-plates in accordance with document 1. 2. Modify: Before 1 July 1977.