COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 185 Series Aeroplanes AD/CESSNA 185/34 Fuel Cap Alignment Placard 9/80 Applicability: Model 185 with S/Nos. 632, 185-0001 to 185-1599 and 18501600 to 18503988. Requirement: Action in accordance with Cessna SIL No. SE 80-59. Compliance: Within 100 hours time in service after 30 September 1980. Background: Correct alignment of flush fitting type fuel caps is essential for efficient operation of the fuel tank secondary vent system.