I don't know if it's possible either, but I'll bet that there are many freeware (and payware) plane designers out there that really don't want to see this kind of program becoming available, for the obvious reasons. If designers' model files could be reverse-engineered, we'd probably see a rapid decline in the willingness of people to design aeroplane models in the first place, if their design was no longer safely locked away in the .mdl file. This could be an enormous blow to the flight sim community as the supply of new models might then dry up.
The only current way to get access to the source code for models is to contact the designer and ask them if they'll give it to you. My suspicion is though, that the answer you get would reflect the level of contentment they would feel at seeing a .mdl-cracking program in the public domain.
GunnerMan, I'm certainly not casting aspersions on your intentions here, believe me - but there are those 'out there' on the WWW whose intentions may not be so honourable. A quote from the forum reference that Wozza gave says it all, really:
"In short, anything much more complex that a box is not at serious risk of being "stolen" using this method... 8-)"
