Autocontrol II Update

 

I have been working to understand how the Omni-Coupler works in the AutoControl II system.  This is old legacy hardware that is not of any real practical use.  My aircraft has it and it works (except for the coupler.)  It turns out that the PA-24-250 parts manual has a complete list of the exact parts required along with a picture (shown.)

It turns out that the coupler needs an input from the heading indicator in order to ensure that the left/right indication from the CDI is treated properly.  The signal from the heading indicator is mixed with the CDI to provide a 45 degree intercept at maximum deflection and this slowly reduces down to zero once on the track.

So, in order to track a course the heading indicator must be set to that course.