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/20 Amdt 1 Undercarriage Operating Tube - Inspection 11/67 Applicability: Anson and Avro 19. Document: Avro TSB No. 80 paragraph 3.6. Compliance: At intervals not exceeding 100 hours time in service.