[PAR] [TLE] Bell X-1 [SEP] The Bell X-1 was a rocket engine-powered aircraft, designated originally as the XS-1, and was a joint National Advisory Committee for Aeronautics-U.S. Army Air Forces-U.S. Air Force supersonic research project built by Bell Aircraft.  Conceived during 1944 and designed and built in 1945, it achieved a speed of nearly 1000 mph in 1948.  A derivative of this same design, the Bell X-1A, having greater fuel capacity and hence longer rocket burning time, exceeded 1600 mph in 1954.  The X-1, piloted by Chuck Yeager, was the first manned airplane to exceed the speed of sound in level flight and was the first of the X-planes, a series of American experimental rocket planes (and non-rocket planes) designated for testing of new technologies and often kept secret. [PAR] [TLE] Chuck Yeager [SEP] Charles Elwood "Chuck" Yeager ( ; born February 13 , 1923) is a former United States Air Force general officer and record-setting test pilot.  In 1947, he became the first pilot confirmed to have exceeded the speed of sound in level flight.
[PAR] [TLE] Bell X-1 [ SEP ] The Bell X-1 was a rocket engine - powered aircraft , designated originally as the XS-1 , and was a joint National Advisory Committee for Aeronautics - U.S. Army Air Forces - U.S. Air Force supersonic research project built by Bell Aircraft . Conceived during 1944 and designed and built in 1945 , it achieved a speed of nearly 1000 mph in 1948 . A derivative of this same design , the Bell X-1A , having greater fuel capacity and hence longer rocket burning time , exceeded 1600 mph in 1954 . The X-1 , piloted by Chuck Yeager , was the first manned airplane to exceed the speed of sound in level flight and was the first of the X - planes , a series of American experimental rocket planes ( and non - rocket planes ) designated for testing of new technologies and often kept secret . [PAR] [TLE] Chuck Yeager [ SEP ] Charles Elwood " Chuck " Yeager ( ; born February 13 , 1923 ) is a former United States Air Force general officer and record - setting test pilot . In 1947 , he became the first pilot confirmed to have exceeded the speed of sound in level flight .
The Bell X-1 was an aircraft piloted at a supersonic level by the test pilot who served in what branch of the armed forces?
The Bell X-1 was an aircraft piloted at a supersonic level by the test pilot who served in what branch of the armed forces ?
United States Air Force
United States Air Force