COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AMD Falcon 50 and 900 Series Aeroplanes AD/AMD 50/2 Booster Pump Crossfeed Valve Actuators 6/86 Applicability: 1. All model AMD Falcon 50 aeroplanes S/Nos 2 to 146, 148 to 158, 160 to 162. Requirement: Action in accordance with Service Bulletin AMD/BA F50-182. Bureau Veritas AD 86-55-4 (B) refers. Compliance: Before further flight after 30 June 1986. Background: Water entrapment in the Aviac actuators P/No.2773 has resulted in a dormant failure of the booster crossfeed valve. The engine which had its feed system fail could not be supplied from the feed system of one of the other engines.