From Wikipedia:

Advanced Pilot Training placed the graduates in two categories: single-engined and multi-engined. Single-engined pilots flew fighters and fighter-bombers. Multi-engined pilots learned to fly transports and bombers. First they flew Trainer aircraft, then transitioned to front-line aircraft. Those students selected for single-engine training flew the AT-6 “Texan,” and those who went into twin-engine training flew the Curtiss AT-9 “Jeep,” the all-wood Beechcraft AT-10 “Wichita,” or the Cessna AT-17 “Bobcat.”^[1]