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-3/4 Cargo Door Handles NK Applicability: All models with S/Nos 2 to 31 except 24. Requirement: Action in accordance with De H Canada TNS Otter no 21. Note: Canadian AD 54-7 refers. Compliance: Forthwith.