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 104/10 Amdt 1 Applicability: All models. Mainplane Upper and Lower Spar Booms - Inspection 2/73 Requirement: 1. Inspect the wing upper and lower spar booms for signs of corrosion, and carry out any necessary repairs, in accordance with Hawker Siddeley Aviation Technical News Sheet CT(104) No. 125 Issue 6. 2. All instances of corrosion are to be reported to the Secretary. Compliance: Between ribs 5 and 7 - within 6 months of the previous inspection (DCA/DH 104/10) and thereafter at intervals not exceeding 6 months. Inboard of rib 5 and outboard of rib 7 - within 12 months of the previous inspection (DCA/DH 104/10) and thereafter at intervals not exceeding 12 months.