The first person to officially break the sound barrier in level flight was Chuck Yeager. On October 14, 1947, Yeager, a United States Air Force test pilot, flew the Bell X-1 rocket-powered aircraft, named Glamorous Glennis, faster than the speed of sound. This historic flight took place at Muroc Army Air Field (now Edwards Air Force Base) in California.
Chuck Yeager's achievement in breaking the sound barrier marked a significant milestone in aviation history and paved the way for supersonic flight. It demonstrated that controlled, level flight at speeds exceeding the speed of sound was possible.
Scott Crossfield, another renowned American test pilot, made important contributions to aviation and supersonic flight but did not break the sound barrier before Yeager. Crossfield played a vital role in flight testing the North American X-15, an experimental aircraft that achieved much higher speeds than the X-1, but Yeager was the first to accomplish supersonic flight in level flight.