Jack Allison wrote:
jmk wrote:

Are you saying it doesn't work in ROLL mode, but does work in HDG mode?
Unusual, but if so then it's a pretty simple fix. The HDG switch
essentially disables the ROLL pot, so if it works okay in HDG but not
in ROLL, then either the switch is bad, or the POT is bad, not much
else involved.

Sorry, I should have clarified. Heading mode works, roll works (sort
of, I'll explain in a sec.). It is the other modes (NAV, OMNI, LOC, LOC
back course) that don't work.

For roll mode, if I turn the round roll knob slightly one direction, the
ailerons keep moving to the stops. If the knob is centered though, the
ailerons stay centered. I've only tried this on the ground. In the
air, heading mode works fine but none of the other modes mentioned above.

That's OK - the autopilot rolls till the roll feedback
from the horizon gyro matches the request from the pot.

You're ordering a certain amount of roll. If the horizon
does not follow, turn more on the ailerons till the order
is fulfilled.

--

Tauno Voipio (CPL(A) - avionics engineer)
tauno voipio (at) iki fi