Mind you I'm not sure that a load of embittered ex squaddies would really fit the bill either. How about selecting people on the basis of their ability to fit in? Flying airliners does not really call for the ability to dodge missiles or SAS survival techniques as a prerequisite.
Well, that is one extreme end of the spectrum zeddb! I was thinking of something a bit nearer the middle, no reason for the troops to be embittered! Just happy at having completed five years of character building stuff they then had the opportunity to go flying, if they are up to it!