BT-13 ValiantVultee BT 13 Valiant airplane model. The BT 13 Valiant was a World War II era basic trainer aircraft built by Vultee Aircraft for the United States Army Air Corps. The Vultee BT 13 was the basic trainer flow by most pilots during WWII. It was the second phase of the three phase training program for pilots. After primary training, the student pilot moved to the more complex Vultee. The BT 13 had a more powerful engine and was faster and heavier than