Corky Scott wrote:

I just tried using the AP on the C172SP I rent from the local FBO last
time I flew, about two weeks ago. I'd never actually used it during
training or in the two years since I got my pilots license, and I
always wanted to try it.

So two weeks ago I did the preflight checkout of the unit, and then
took off and climbed to 3000 feet. I punched in the "AP" button, the
"ALT" button and selected "Heading" as a choice. Then I sat back and
watched while it turned the few degrees needed to lock to the
Directional Gyro's heading and held it there while sticking precisely
to 3,000 feet. The morning was hot and moist and very very still so
the AP had little work to do once it got where it was set.

Yeah, it's too bad we don't usually get instruction in how to use these things.
If you're going to self-instruct be sure to explore the edges of what happens in
altitude-hold when the airspeed bleeds off. Does it disconnect, or fly you into
a stall, or what?

Self-instruction is better than no instruction at all, and may be better than
what you would get if you asked an instructor.

Dave