COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DH114 (Heron) Series Aeroplanes AD/DH114/46 Fuel System - Modification 6/85 TX Applicability: DH114 model 2D/A1 aircraft which have been in modified in accordance with AVDEV Airlines drawing No AA17. Requirement: 1. Isolate outboard tank system in accordance with East Coast Airlines E.O. Sydney Q2/84 issue 2, or 2. Modify fuel system in a manner acceptable to the Secretary. 3. Approval of AVDEV Airlines Drawing No AA17 is withdrawn. Compliance: Before further flight. Background: The modified fuel system has been found not to comply with BCAR section D5-2.