Autopilot Servo

[Bob Cook]

The autopilot is basically the same. The actual servos are very similiar, however, there is a little more complexity.

The acid test is flying with the steering know on the ground or in the air. You isolate the heading reference portion of the system. Yours problem if intermittent is more likely a dirty follower pot in the servo. You can measure with an ohmeter while moving aileron on the ground. i can give pin numbers.

Other problem would be the reference voltage (-10 volts DC) see pin numbers. Other causes can be broken wire or dirty connectors..

The 400 computer is more complex and the power supplies on the 400A were not very stable but once working they seemed to work forever. Once stable with the turn pot controlling the aircraft and problem still exists then it is more likely to be the Pickoff coils in the AI. Need more information as to how the AC reacts before I can give you help.

My 400 B with IFCS works like a charm and is rock solid. Does full intercepts with ILS hands off. They just need a little TLC and when working are far better than the S-TEC which is a roll rate device.... ARG!

get me the computer number and I probably have the manuals for it here. Does it have three switches on the right side one above the other ?


Bob