Well, as you already know the first stage was all of the aptitude tests, which people say you can't prepare for but I feel that the more you do them the better you get cos you get used to the time limitations. You also learn to skip past questions that'd take to long and only answer if you are sure, since I think most of such tests involve negative marking.
The second stage had three parts:
2 group excercises and phsycometrics. The first group task involved an imaginary situation where the company was moving site to somewhere else, and there was a huge pile of metal tacks at the new site that had to be disposed of. The disposal method had to be good for the company, the local area and perhaps a charity. As most people would tell you, be vocal but don't try to control the group. Try and be organised and keep one eye on the main objectives so that you don't go astray.
The second task was a kind of 'lego' one using coloured tubes. I would give advice here but it was all a bit frantic! No doubt it's just a check on your team work ability. Again, be vocal so the HR people can hear you and you'll find it's actually quite fun!
As for the personality tests, just answer truthfully I suppose, though I guess it'd be best not to come across as being anti-social and as having little confidence?
I found the final interviews were both quite similar. As in both asked about uni, family life and personal life. No situational stuff, no questions about the company and surprisingly not too much about flying (principles of that is, there was a bit about flying experience).
And, well, thats it really, or my take on things at least. I'm sure other people might have found things to be different or have differing advice to give. Hope it helps.
Oh and sorry for spelling mistakes, i'm at work so have to type quickly!
Cam