COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Avro Anson and Avro 19 Series Aeroplanes AD/ANSON/10 Fuel Crossfeed Cock - Inspection 3/52 Applicability: Anson. Requirement: Inspect the fuel crossfeed cock and ensure that the stop ring is NOT in a position which will prevent the cock from being moved to the 'OFF' position; or ANO 105.1.31.4.6.2. Compliance: At any time the fuel crossfeed cock is disturbed.