Navomatic AF-420A

[n86121]

I have become intimate with the navomatic autopilot in my T337D over the years, and have the full install and maintenance manual. AND I'm a nerd. Let me know if I can help.

The switch (GYRO ON/OFF) on the back of the control head
should be OPEN, only for setting the zero / null positions on the servos
to temporarily disconnect 'error' signal from the gyros,
then for normal operation, CLOSED
to re-connect the error signals coming from the DG heading gyro and horizon.

If you need some unofficial ways to zero out the servos, let me know....