COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/24 Propeller Attachment - Modification and Inspection 4/69 Applicability: All model HC-A3VF series propellers fitted to Continental GTS10-520 series engines. Requirement: 1. Replace propeller mounting bolts and washers with P/No.A-1328-1 bolts and P/No. A-1381 washers and torque to 80-85 pounds feet. 2. Check for loss of torque on the propeller mounting bolts by applying a measured torque of 80-85 pounds feet. 3. In the event of any substantial loss of torque of the mounting bolts being found, or of excessive rough running being experienced from the associated engine, remove the propeller and inspect the mounting bolts and dowels, propeller attachment face and propeller shaft flange for signs of cracking or excessive fretting. When such indications are found, replace all mounting bolts and dowels with new items. Compliance: For Para. 1 - Within 10 hours time in service after 15 April 1969 unless previously accomplished. For Para. 2 - At intervals not exceeding 100 hours time in service. For Para. 3 - As required.