COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-36 (Pawnee Brave) Series Aeroplanes AD/PA-36/17 Rudder Spar - Inspection 4/77 Applicability: All models with S/Nos. 36-7360001 to 36-7760003. Document: Piper SB No. 518. Compliance: Within 100 hours time in service after 30 April 1977 and thereafter at intervals not exceeding 100 hours time in service until rudder is replaced.