You sign a contract saying you will work anyway, if you can not accept that do not sign it.
Nobody apart from the people dealing with postings know exactly how they decide on them, but there are no gaurantees. For example, as I've understood it, if Gatwick does not want/need a trainee you will not be posted there and that is the end of the story. You might be posted somewhere close (such as City or Heathrow) but you might also be posted to Aberdeen.
And this is all presuming you end up training for Aerodrome and not area, which is the same story again.
You get to hand in a preference, but there are no gaurantees.
Last edited by Crazy Voyager; 16th Aug 2013 at 21:25.