Boeing 367-80

The Boeing 367-80, known as the Dash 80, was a four-engined American prototype jet aircraft built by Boeing to show the advantages of jet propulsion for commercial aviation. It became the basis for the design of the KC-135 tanker and the 707 airliner. It first flew on 15 July 1954, less than two years after the project began, and its cost of 16 million US dollars was a very large risk for Boeing, which had no committed customers at the time. Only one example was built. It has been retired and is preserved on public display at the Smithsonian National Air and Space Museum Udvar-Hazy Center in Virginia.