"Michael" wrote:
Without GPSS, an STEC might as well be a decades-old
Autocontrol/Altimatic - it will hunt so much in nav track mode that
you
will wind up just using it in heading hold mode.

Something's wrong with your student's S-Tec installation.

Mine doesn't have GPSS, but when it's set to "Approach" mode and the CDI
scale is set at one mile, it will hold me within 50' of my course line
for 100's of miles without hunting.

If I let the autopilot turn me to a new heading, it will hunt for a
while. GPSS would fix this, but I can't bring myself to pony up the
$1800 to add it.

I'm not that impressed with the altitude hold function. The
installation I've seen lacks auto-trim. I would say that if you have
a
Mooney without electric trim, the altitude hold is not worth buying.
If the air is smooth, a properly trimmed plane will hold altitude
anyway. If it's not, constantly retrimming when the thing beeps at
you
isn't any less work than just holding altitude manually.

Once again, this doesn't sound right. Turbulence has to be pretty close
to moderate before I'll turn altitude hold off.
--
Dan
C172RG at BFM