Go to this page (realflight's web site):

[link]http://www.bestrc.com/hobbies-bin/rfaircraftread.pl?&page=8[/link]

4th one up from the bottom is the "TTRappy10". Download this into a temp file, then go to the file and double-click (it is self installing). Open up RealFlight, and it will be toward the bottom of the helis. This one is based on the 30, but you can go in and edit everything to get close to the 50 (engine choice is the OS46, so not quite as powerful as it should be). Lengthen the boom, blades, set up your gyro, etc. After getting mine set up, in flies surprisingly close to my 50v2.