COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-28 Series Aeroplanes AD/PA-28/58 Wing Structural Fatigue Life Limitation 12/76 Applicability: All model PA-28-235. Requirement: Retire the wing from service. Compliance: At or before 12,500 hours time in service.