COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Gates Learjet 24 & 25 Series Aeroplanes AD/LEARJET/12 Control System Stop Bolts - Replacement 9/75 Applicability: All model 24 with S/Nos. 24-100 to 24-304 and 24-309 to 24-322, and all model 25 with S/Nos. 25-003 to 25-197. Document: Gates Learjet SB 23/24/25-266. Compliance: Within 300 hours time in service after 31 October 1975.