Chuck Yeager breaks the sound barrier in Bell X-1

On October 14, 1947, U.S. Air Force Captain Chuck Yeager became the first person to break the sound barrier in level flight. Flying the Bell X-1, a rocket-powered aircraft nicknamed ‘Glamorous Glennis’, Yeager reached a speed of Mach 1.07, approximately 821 mph.

The Bell X-1 was an experimental project involving the National Advisory Committee for Aeronautics (NACA), the predecessor to NASA, and the U.S. Army Air Forces. The aircraft was dropped from a Boeing B-29 bomber before its rocket engine, fueled by liquid oxygen and ethyl alcohol, propelled it to supersonic speeds.

Yeager completed the historic flight despite having broken two ribs in a horse-riding accident the previous night. This achievement transitioned supersonic flight from a theoretical concept into a reality, fundamentally changing the course of aviation history.