flying X-1 #2 (USAAF s/n 46-063), but did not exceed Mach 1. However, the Army Air Force came to feel that Bell’s test ...

A joint project of NACA and the U.S. Army Air Forces, built by Bell Aircraft of Buffalo, New York, the X-1 reached a speed of 700 miles per hour that bright day, Mach 1.06 at an altitude of 43,000 ...

the Bell Experimental Sonic (XS)-1, explored transonic and low supersonic speeds. On October 14, 1947, the X-1 reached Mach 1.06, the first aircraft to exceed the speed of sound in controlled ...