Dave Rogers, a professor at the USNA, Annapolis, has done a lot of
work on this problem.

See http://web.usna.navy.mil/~dfr/flying/possible.html

or Google "impossible turn."

One good idea is to add "Turnback altitude" as the last item on your
takeoff check list, and say that altitide aloud, so you have it in
mind as you climb out.

Another is to consciously note any crosswind on takeoff; make your
turn into the wind when the enngine quits.

vince norris