At 25 you should still be okay and dare I say it have enough time to get your foot on the property ladder. Even with a prospective downturn in the property markets at least you will have acquired something and if nothing else you will have already acquired an asset for life. Why not purchase it now and then rent it out to tennats while you share with your understanding other half (girlfriend/wife/mistress/all
) or failing that move in with your parents. The mortgage will reduce in a couple of years whilst you concentrate on spending your money on pilot training.
Don't forget that the aviation aspect of this argument is far more riskier and unstable than the property market even during leaner times. Once you're qualified you're going to want a property anyway so why not go ahead and get it now whilst you still have the chance, remember you can sell it at any time too should circumstances dictate.
It's a touch distressing when people are blinded by the prospect of a career at the expense of all other opportunities in life. With clever and realistic planning you can have your cake and eat it too. See if you can also get as many people around you to help you'll be surprised how many options that gives rise to.
Anyway best of luck with whatever you decide.