COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 185 Series Aeroplanes AD/CESSNA 185/18 Wing Strut Attachment Strap 9/73 Applicability: All model 185 with S/Nos. 18502199 to 18502238. Requirement: Action in accordance with Cessna SL SE73-20. Compliance: Within 100 hours time in service after 24 September 1973.