COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DH 104 (Dove) Series Aeroplanes AD/DH 104/19 Amdt 1 Engine Mounting Frames - Inspection 8/71 Applicability: All models fitted with engine mount frames No. 4EM201A and 4EM203A. Requirement: Inspect the engine mounting frames for evidence of internal corrosion by visual and radiographic means. Note: The inspections shall be carried out in accordance with Hawker Siddeley TNS CT(104) No. 190 Issue 2. Radiographs and any associated reports shall be submitted to the Secretary for examination. Compliance: At intervals not exceeding 4 years.