I think that you need to ask somebody else - this is an engineers forum, and speaking for myself I'm an aeronautical engineer who occasionally test flies light aeroplanes. Airlines are things that keep many colleagues in gainful employment, but for me are generally just public transport. That said, the question is what you want a backup for - if you want to work in the aircraft industry, go for aero-eng, if there's nothing in aviation that interests you apart from flying a 300 seat heavy then (a) in my opinion you're shortsighted, and (b) do something totally vocational - become a personal trainer, accountant, chef - something like that as your backup.
The Salford degree is accredited by the RAeS, but there may well be many other good reasons not to go there (still living with your parents possibly high on the list as well!).
For my money, Liverpool or Brunel would be the plum choices for the combined degree programme in this country, Embry-Riddle if you can afford to study in the USA.
G