COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes AD/AC/6 Fuel Vent and Vapour Return Lines - Modification NK Applicability: Models 560A and 680: S/Nos. 231 to 580 except 466, 471, 492, 509, 523, 547, 568, 570, 572, 574, 576, 579. Document: 1. Aero Commander SB No. 45; or 2. FAA AD 58-1-1. Compliance: Forthwith.