Practice varies. I can only report what I was told - that military
aircraft training in MOAs near Phoenix are either not equipped with any
transponder-sensing electronics or do not use them and that flights are
primarily visual. Military controllers do not actively monitor
aircraft in our MOAs, merely handling exit from and return to the
airport.

We have no choice of where to fly from our home field - high ground to
the north, controlled airspace to the east and south forces us into the
MOAs, which cover huge areas of all western states. If we don't fly in
the MOAs, we don't fly anywhere.

Mike