COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters AD/HU 369/11 Amdt 1 Main Transmission Ring Gear Bolts - Inspection 2/79 Applicability: All model 369H Series except helicopters modified in accordance with HL. 39 (main transmission P/N 369A5100- 705M, -707M, -709). Document: Hughes SIN No. HN-61. Compliance: At next scheduled main transmission oil change and thereafter at intervals not exceeding 150 hours time in service after 28 September 1973.