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/3 Boost Gauge - Modification 2/51 Applicability: Anson. Document: 1. A.V. Roe Anson Mod. No. 122; or 2. RAAF Anson Order No. 4; or 3. ANO 105.1.31.4.5.3. Compliance: Forthwith.