COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Airparts (NZ) Ltd. FU 24 Series Aeroplanes AD/FU24/12 Rudder Lowr Rib - Inspection 6/68 Applicability: All models not incorporating James Aviation Mod. HA/FU24/116. Requirement: Detach the torque tube from the rudder and examine the rudder lower rib assembly P/N 242406 at the attachment of the rudder torque tube flange P/N 242410 for cracking and corrosion. Compliance: At intervals not exceeding 500 hours time in service.