I'm ex military. Anhony Carn hits the nail spot on.
Try to live closer to Luton. Then if you have to work at Stansted you can, and if you have to be based at LHR you can, and if you are at LGW then you can (just), and if you have to work BHX , Coventry, EMA or MAN you could probably drive most of the time. If you end up abroad for a while you can travel from LHR easily etc.
It is very unlikely that your company/ies will give you an easy time on base location over a period of say 25years. Don't move house to suit the company - companies come and go with recessions, mergers and so on. Don.t believe anything your manager/chief pilot says - he may be genuine, but tomorrow he could be out and somebody new is in. Most managers in civilian life are not nearly as professional or as well educated or have the bread of experience that you will be used to having as a matter of routine in the forces. You'll be lucky if they have done more than the odd two or three day course covering their management role. Most managers, like staff are expendable - terms of notice are in everyones contract.
Even choosing a profitable expanding carrier is no guarantee to stability - somebody might offer the airline owner/shareholders lots of money for the airport slots for examople - your job disappears overnight. You will probably read it in the press before you get the letter in your mail slot (unlikely to be sent 1st class post to your home).
You may think I'm bitter. I'm not. I love my job, and my past jobs (and I've had 4 unscripted employer changes in 18 years). Don't come into this business expecting 'someone' higher up to be 'looking after you.' You are on your own - part of the beauty of it all after the forces.