COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 400 Series Aeroplanes AD/CESSNA 400/53 Auto Pilot System - Disabling - Modification 6/78 Applicability: Models 402B S/Nos. 402B1001 thru 402B1331 and 402B1333 thru 402B1338; 404 S/Nos. 404-0001 thru 404-0218 and 404-0220 thru 404-0222; 414 and 414A S/Nos. 414-0801 thru 414-0965, 414A0001 thru 414A0032, 414A0034 thru 414A0038 and 414A0040 thru 414A0047; 421C S/Nos. 421C0001 thru 421C0479 and 421C0481 thru 421C0488; incorporating ARC model 400B auto pilot installations. Requirement: 1. On aircraft not modified in accordance with Cessna SL No. AV78-6 dated 31 March 1978 or later revision, disable the model 400B auto pilot by pulling and banding AUTO PILOT COMPUTER (COMP) and ACTUATOR (ACT) circuit breakers. 2. Install a placard in plain view of the pilot indicating "AUTO PILOT INOPERATIVE". 3. Upon accomplishment of the electrical auto pilot actuator modification set out in Cessna SL No. AV78-6, the auto pilot may be returned to service and the "AUTO PILOT INOPERATIVE" placard removed. Compliance: Paras. 1 and 2 - Before further flight. Para. 3 - Before further flight using autopilot.