COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 500 (Citation) Series Aeroplanes AD/CESSNA 500/4 Amdt 1 Flight Compartment Side Windows - Inspection and Replacement 11/74 Applicability: All model 500 except those fitted with flight compartment side windows P/Nos. 5511285-34-4. Requirement: 1. Inspect in accordance with Cessna Citation SL 56-2 Rev. 1. 2. Replace in accordance with SB 56-4. Compliance: Before achieving 400 hours time in service and thereafter at intervals not exceeding 100 hours time in service until modified. Modify before 1 September 1975.