The first hurdle you'll need to get over is explaining why you only stayed 5 months last time around...
You're going for Aircrew. One assumes you weren't Aircrew before and one also assumes you weren't being officer trained, (if you were being officer trained then the explanation might be simple).
Now you are going for aircrew, (not wishing to start a p1ssing match), the best the RAF has to offer. If you backed out previously what can you bring to the table this time to convince me that you won't spend a few weeks hanging out with the "elite" before going home to mummy again? If you were failed in training what are you bringing to the table this time to convince me you can pass a series of courses that, most probably, will be much more difficult physically and mentally that the one you were kicked off last time around?
Harsh? Maybe... But if you don't have convincing answers then looking for a job in 19 weeks is a non-issue.