[alberich]

Hm. I thought the post was referring the troubles of maneauviring during a slowdown, as airplanes can only go forward.

If falling of the sky is the trouble, you can still use parachutes as a safety measure. Like this one (http://en.wikipedia.org/wiki/Ballistic_Recovery_Systems).

Anyways, I don't think flying cars are impossible. We just don't have enough technology yet to make it viable.