Personally, being 28 and my parents being close to retirement the last thing I wish to do is ask them for assistance in this (by way of securing any borrowing against their property / otherwise).
Obviously the cadet still takes on the debt and is responsible for the repayments (unless declared bankrupt etc.).
Absolutely BBVA are unique in their repayment schedule, the perks of a product created specifically for flight training.
I think anyone going into this process, nevermind accepting a training position, is entirely aware of the financial burden that will undoubtedly make the first few years post-qual hard work. At least I hope this is the case....
I do wonder with other lenders whether or not you could boost the amount borrowed to cover the initial payments. Though this would probably amount to 20k odd and would be hard to justify to the lender.