During the early 1950's, my father was a flight instructor for Texas Aviation Industries (TAI) in Hondo Tx. At the time, they were flying T6's, training Air Force students to solo. I remember the training was very vigirous, and they were not allowed to solo until they could exhibit skills in spin, spin recovery and basic aerobatics. They did quite a bit of night flying, and you could hear them for miles when they would bring the engine up to max manifold pressure and exercise the prop. Eventually they went to T28's. Some years later, he solo'ed me in a Champ, and whenever he would tell me to perform a two turn spin, he meant two turns, no more, no less. I've been flying, strictly for pleasure, ever since. Jim