COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES GAF N22 and N24 Series Aeroplanes AD/GAF-N22/26 Rudder Tab Mass Balance Hinge Pin - Inspection 5/79 Applicability: All models N22, N22B, N24 and N24A with Mod. N39 fitted and delivered before 1 March 1979. Document: GAF Alert SB No. ANMD-55-6. Compliance: Within 50 hours time in service after 16 March 1979 and thereafter at intervals not exceeding 100 hours time in service until modified in accordance with Alert SB No. ANMD-55-6. Background: An instance has occurred where the rudder tab mass balance hinge pin seized in its bush and sheared the split pin retaining the hinge pin.