COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES British Aerospace (Scottish Aviation) Twin Pioneer Series Aeroplanes AD/SA-TP/11 Ice Guard on CSU Swivel Assembly NK Applicability: All Series 1 and 3. Document: Scottish Aviation Mod. No. C680. Compliance: Forthwith.