COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pilatus Porter PC-6 Series Aeroplanes AD/PC-6/15 Aileron Cable Pulley - Modification 1/67 Applicability: All models prior to S/No. 633. Document: Pilatus SB No. 68. Compliance: Before 31 March 1967.