COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron 47 (All Variants) Series Helicopters AD/BELL 47/65 Duplex Pitch Change Bearing - Inspection and Retirement 8/70 Applicability: All model 47D-1, 47G, 47G-2 and 47H-1 fitted with duplex pitch change bearing P/N 47-641-131-1. Requirement: 1. Inspection: Dismantle the tail rotor drive head sufficiently to expose the duplex pitch change bearings and guide sleeve P/N 47-641-040 or 47-641-130. 1.1. Inspect the outside surface of the guide sleeve for scoring. 1.2. Inspect the duplex bearing for roughness. 2. Retirement: Replace duplex pitch change bearings P/N 47-641-131-1. Note: FAA AD 70-14-1 also refers. Compliance: For Para. 1 - Within 100 hours time in service after 31 August 1970. For Para. 2 - At intervals not exceeding 600 hours total time in service.