Honeywell KFC-225 autopilot - what could cause this failure?

Hi Peter,

No watchdog? Ouch. How did they ever get this certified?



Easy, general aviation autopilots are permitted to fail at any time,
without a warning, in any way whatsoever.


Wow. They'd never let us get away with that in medical electronics. Even
after a defibrillator hit many systems must come back to normal
operation within a prescribed time frame.

The servo clutches are supposed to be always possible to overpower,
and the pitch *trim* subsystem is supposed to warn the pilot if the
trim has been running out of control (because an excessively out of
trim condition might require more yoke force to overpower than a pilot
can physically manage). But I think those are the only certification
requirements for TSO.


I knew about the servo clutches, without override the airplane would
probably become uncontrollable if the AP fails to disengage for some
reason. But I still can't believe that the amplifiers blow.

Regards, Joerg

http://www.analogconsultants.com