"Craig Prouse" wrote in message ...

If I recall correctly, those S-Tec autopilots require the pilot to establish
the aircraft on course before engaging the NAV course tracking mode. Once
on course, the error signal from the CDI is probably sufficient to remain
there.

Depends which model you have. The 20/30 will not intercept a course, just hold it.
The more expensive ones in the line will intercept the course.