COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 700) Series Aeroplanes AD/AC/25 Circuit Breaker Panel - Insulator Inspection 6/62 Applicability: Models 520, 560, 560A, 560E, 500 and 680 with S/Nos. 1 to 892. Document: Aero Commander SL No. 123. Compliance: At intervals not exceeding 100 hours' time in service.