COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-24 (Comanche) Series Aeroplanes AD/PA-24/37 Stabilator Balance Weight Tube - Replacement 8/76 Applicability: All models with stabilator modification kit Piper P/N 760747 installed per Piper SL No. 687. Document: Piper SB No. 496. Compliance: Within 100 hours time in service after 31 August 1976.