Although jets began replacing prop aircraft in the USAF inventory in the late 1940s, the service continued using propeller-driven trainers for primary training until April 1961—aircraft like the T-6, the T-28, and the T-34. So what happened in 1961 to lure the USAF into dropping piston-engine trainers? By that time, the Cessna twin-jet T-37 had proven itself as a primary trainer, prompting the USAF to experiment with an "all-through jet" training syllabus. Officials figured the new jet trainer was so easy and cheap to fly, propeller-driven trainers were no longer needed. Besides, with a soon-to-be-all-jet inventory, why train with propeller-driven anachronisms?

As with so many seemingly well-thought-out plans, reality soon intervened. The USAF discovered that even the T-37, despite its small 1,025-pound-thrust turbojets, cost too much to operate in that entry-level pilot screening role. Students who were unable to overcome physiological deficiencies (such things as active airsickness, claustrophobia, fear of flying, etc.), who were incapable of attaining the required proficiency in the time allotted, or who were merely unsuited for the regimentation of military flying used up a lot of expensive resources before being eliminated from training.

After only three years of the all-jet experiment, the USAF's Air Training Command (ATC) set about reinventing the wheel and went shopping for a piston-engine trainer. When the military reinvents the wheel it tends to reinvent the whole concept of round. So, the USAF decided that the new trainers should be flown and maintained by civilian flight schools under government contracts…