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/8 Main Landing Gear Upper Strut - Inspection 3/75 Applicability: Model 24 with S/Nos. 24-100 to 24-297; and model 25 with S/Nos. 25-003 to 25-182. Requirement: To detect cracks or flaws in the MLG upper strut:- 1. Remove strut from aeroplane, dismantle, clean and inspect using a Fluorescent Dye Penetrant Technique. 2. If cracks or flaws are disclosed by the inspection in para. 1 evaluate the position of cracks or flaws as per Fig. 1 of Gates Learjet SB No. 23/24/25-259; reject or rework affected upper struts as specified. Compliance: Within 600 hours time in service after 30 April 1975 or 30 September 1976 whichever occurs first.