COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-22 (Tri-Pacer and Colt) Series Aeroplanes AD/PA-22/1 Landing Gear Reinforcement NK Applicability: Models PA-22 and PA-22-135 except S/Nos. 22-2377, 2379, 2385, 2388, 2389, 2391, 2394 and above. Document: 1. Piper SL No. 124; or 2. FAA AD 55-7-2. Compliance: Forthwith.