AoM,
I am not privy to how they go about selecting one guy over another exactly. I do know that some good guys have applied through CTC and have got nowhere but that's another issue. At the moment there are a few Baby and Flybe guys going through the system and by all accounts they are all good guys.
If you worked there before then surely it's worth contacting them again as they know you - what do you have to lose? You could always try explaining why you left in the first place and see if they will have you back...... unless of course you buggered off without repaying the bond!
Good luck!