well as for the actual physical model, a good plane can be created in 3DSM, Blender, MS3D, etc. Now if that model could be converted to a game friendly format then modified by HTC, it could save them SOME trouble. for example someone creates a P-61.
Next if they set the meshes to the correct names:
Fuselage, Cockpit, Engine 1, Engine 2 etc.
Well then HTC could convert, animate, etc couldnt they? Just my 2c. then again I'm more a level designer lmao.