COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Dowty Rotol AD/PR/20 Hub Front Face to Snout Radius - Inspection NK Applicability: All model (c) R175/4-30-4/13E, (c) R186/4-30-4/16 and 16/1, (c) R212/4-30-4/22/1 propellers not modified in accordance with Mod. VP 2388. Requirement: In accordance with an approved eddy current technique, inspect the hub front face to dome mount radius for cracking. Compliance: For all propellers which have not been modified in accordance with Mod. VP 2388 - inspect in accordance with the requirement within 1500 hours time in service after 30 September 1978, and thereafter at intervals not exceeding 1500 hours. Note: NAC Eddy Current Technique TB-61-10 F3201 NAC9 is an approved technique.