This was a very entertaining simulation of Unlimited-class air racing in highly-modded P-51s etc. While the GUIs were crude, the action was hot and heavy and there was a great replay feature.
A "sequel" is now available, with expanded aircraft, aircraft classes and courses. It's a bit better than this reviewer allows:
http://www.gamespot.com/pc/sim/xtremeairracing2/
What are the chances of getting TrackIR support for this deserving sim?