COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DHC-3 (Otter) Series Aeroplanes AD/DHC-3/24 Main Landing Gear Fuselage Attachment Bolts 3/69 Applicability: All models. Requirement: Remove and inspect using a magnetic particle method main landing gear to fuselage attachment bolts P/Ns C3U72-3 and C3U142-5 for cracking particularly around the grease outlet hole. Compliance: Within 100 hours time in service after 15 April 1969 and thereafter at intervals not exceeding 500 hours time in service.