In 1952, believing that jet engine technology had matured to the point that it offered airlines a superior alternative to current piston-engine airplanes, William Allen bet the company on an internally-funded prototype jet transport. Designated the Dash 80, it was the product of more than 150 preliminary designs. It rolled out on May 14, 1954, and served as the flight test and marketing prototype for the slightly wider 707, as well as for the KC-135 tanker.