COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DH114 (Heron) Series Aeroplanes AD/DH114/36 Outer Engine Mounting Attachment NK Fittings - Inspection Applicability: All models. Document: Hawker Siddeley TNS Heron (114) No. W.18, Issue 1. Compliance: Within 300 hours time in service after 31 May 1972 or before 30 September 1972, whichever occurs first.