The BT-13A was one of several simplified versions of the more complex Vultee BT-54 Basic Trainer. It was a fixed-gear, low-wing tail-dragger with a crew of two sitting in tandom. It was powered by either the Pratt & Whitney R-985-AN-1 or the Wright R-975-11. Both engines delivered 450 hp. When production ended in 1944, approximately 11,537 Valiants had been built. The BT-13 was the most widely used trainer aircraft in WWII. It was flown by most American pilots in transitioning from Primary trainers like the PT-19 to more advanced trainers like the AT-6. It was more complex than the Primary trainer and required the use of two-way radio, landing flaps and a two-position, controllable-pitch prop. The BT-13 was nick-named the “Vultee Vibrator” by its pilots for its most remarkable characteristic- a tendency to shake violently as it approached stall speed. After WWII most Valiants were scrapped but a few were sold to private owners. Today less than 50 are still airworthy and can often be seen at airshows around the country.