"CFII_ASC" wrote:
Bottom line, you have to know what your box does and doesn't do
automatically, and when it does it, and why. An put a check of that
NAV/GPS switch in your set-up procedure for *all* your approaches, not
just the GPS ones.

Yeah, I've been burned by that one, and it's one of the most common
mistakes I see students make.

The other common one (at least on the CNX-80) is to forget to hit the
EXEC button after modifying a flight plan or selecting an approach.