Just read an article on how to take drops 2 to 30ft (Bicycling Mag. June Ed. Pg. 87). It said that you should not lock your front brake while in the air; it will make your bike nosedive. Not that I do that myself, I have no time to pull brake levers while in the air, but why would a bike nose dive if I did? Is it because the wheel stops spinning and it becomes more-less dead weight?