COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - McCauley AD/PMC/42 Oil Filled Hubs for Agricultural Aircraft 13/88 Applicability: All model D2A34C58, D2A34C98 and D3A32C90 series propellers fitted to agricultural aircraft. Requirement: Modify all propeller hubs to dye oil filled standard in accordance with McCauley Service Manual 720415 Supplement No 1. Service Bulletins 122 and 138C refer. Note: FAA AD 78-20-01 and 85-08-08 refer. Compliance: At next propeller overhaul or by 1 December 1989, whichever occurs first. Background: Further hub failures have occurred since revision of the threaded hub dye inspection AD. Due to the load cycles imposed in a hub during agricultural operations and to assist in early detection of hub cracks dye oil filling is being introduced. Propeller TBO has also been reduced to 1200 hours.