"goo" == goo writes:

goo Couple of manufacturers around that I have seen at trade
goo shows. They use MS Flight Sim for demos. try www.servos.com

Regarding X-Plane specifically, there is some commercial use with a
motion platform. I think it's even FAA-approved for certain types of
training, so obviously it's doable. Some companies such as Carter
Copter are using it for design simulation as well. The X-Plane site
should have suitable links or other info though.

--
A hacker does for love what others would not do for money.