COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Schweizer (Hughes) 269 Series Helicopters AD/HU 269/23 Amdt 8 Main Rotor Gear Drive Assembly - Inspection and Replacement 11/81 Applicability: All models fitted with P/N 269A5175, 269A5175-3 or 269A5175-5 main rotor gear drive, incorporating P/N 269A5179 or 269A5179-3 drive shaft. Document: Hughes SIN N-179. Note: FAA AD 81-17-04 refers. Compliance: In accordance with the requirement document. Background: The Directive is raised in issue to reflect current manufacturers data and FAA requirements. Hughes SIN N-179 supersedes N-114-3 N-143, and additionally reduces the life of P/N 269A5179 or 269A5179-3 shaft and coupling assemblies. Installation of P/N 269A5194 carrier assembly(N-142-1) is now mandatory.