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 369/23 Main Rotor Hub Lead Lag Link - Inspection 3/77 Applicability: All 500 model 369H with lead lag links P/Nos. 369A1234, 369A1234-7, 80-369H1234 and lead lag link assembly P/No. 369H1203. Document: Hughes SIN No. HN-109. Compliance: Within 100 hours time in service after 31 March 1977 and thereafter at intervals not exceeding 100 hours time in service.