A friend of mine is quite an expert for Flightsim and Trainsim conversions. He's created many tools for image conversion and manipulation/viewing/printing of extended bitmap formats used in Flightsim and also Trainsim. He's also created plugin for Project Dogwaffle to load those formats into PD directly.

I don't know if he also does 3D stuff for Flightsim/Trainsim, but you might want to contact him about it, his name is Martin Wright (another Wright brother :-)   I forgot his website details but you can probably find it through the links to his plugins at www.thebest3d.com/dogwaffle/3rdpartyplugins - look for Martin Wright's Flightsim plugin, or for MultiPrint

Another thing you might want to do is check if Milkshape3D has it, or ask the mstrainsim forum at Yahoogroups.com