English: Production of U.S. Army Air Forces Vultee BT-13/-15 Valiant trainers at Downey, California (USA), in 1943.
Original description: "(Downey, CA) Their propellers almost touching the next ship's rudder, basic trainer planes flow tail first down the final assembly line - the fastest in the world - in Consolidated Vultee Aircraft's plant here. Eleven nearly completed planes, just part of one day's production, can be counted on this portion of the long powered conveyor line in the factory that is the Army's and Navy's major source of basic trainers and holds the reputation of being the most efficient in the aircraft industry. "