COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - McCauley AD/PMC/43 Blade Shank Corrosion 8/89 Applicability: All McCauley Hubs P/No 41D5926 with blade P/No SS-135-6 or Hub P/No D-1093 with blade P/No SS-135-6M or SS-138-6. Requirement: Disassemble and inspect the hub and blade shank for fatigue cracks using an approved magnetic particle inspection technique. Note 1. The technique detailed in CAO 108-8 is an approved technique. Note 2. FAA AD 54-12-02 refers. Compliance: Unless already accomplished; by 31 August 1989. Thereafter reinspect at intervals not exceeding 100 hours time in service. Background: To ensure fatigue cracking is detected before loss of a blade occurs, a recurring magnetic particle inspection is required. Affected propellers are fitted to Boeing Stearman aircraft and may be fitted to other older style aircraft.