COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piaggio P166 Series Aeroplanes AD/P166/21 Main Landing Gear Shock Absorber Strut - Modification 12/62 Applicability: All model P166. Document: Piaggio SB P166-25A. Compliance: Forthwith.