Smithsonian Air and Space Museum / BellX1- built in 1945 for purely experimental research purposes. Powered by a 4-chambered rocket engine which burned alcohol and liquid oxygen, Richard Erwin                                          the first powered flights began in September, 1946. On October 14, 1947, the plane, piloted by Chuck Yeager, in its 50th flight, became the first manned 8/10/2009                                                 supersonic (faster than sound) aircraft. Dropped from the bomb-bay of a B-29, the plane reached a speed of 807.2 miles per hour.