Orignially desingated XS-1, the X-1 was a joint NACA-US. Army Air Forces/Air Force supersonic research project. What's unique about this experimental aircraft is that it is powered by a rocket engine and that it is the first plane to exceed the speed of sound in controlled and level flight. It's design was like a "bullet with wings"that closely resembled the shape of a Browning .50-calibur (12.7 mm) machine gun bullet. The reason for this resemblance is because it was known that this type of bullet is stable in supersonic flight. The first pilot who achieved a supersonic speed in this aircraft was U.S. Air Force Captain Charles "Chuck" Yeager, on October 14th, 1947, in #46-062, 'Glamorous Glennis'. The plane was christened by him after his wife.
Captain Charles "Chuck" Yeager in front of the Bell X-1, which he christened 'Glamorous Glennis', after his wife.