COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Victa and A.E.S.L. Airtourer Series Aeroplanes AD/VAT/33 Control Column Bearing Spigot Bolt - Inspection 10/68 Applicability: Airtourer 100 and 115. Requirement: Inspect the control column torque tube near bearing spigot bolt P/N 31724/1 for conformity with 6/15-24 WNF-2A threadform. Note: The outside diameter of this thread should be 0.3042 inches minimum and the root diameter should be 0.2536 inches minimum. Compliance: Within 100 hours time in service after 6 October 1968 or before installation after 6 October 1968 whichever occurs first.