On October 14, 1947, US Air Force Captain Chuck Yeager became the first person to break the sound barrier. Working as a test pilot for Bell Aircraft, Yeager’s plane, an X-1, was lifted to an altitude of 25,000 feet by a B-29 aircraft and then released for flight; it rocketed to 40,000 feet where it exceeded 662 miles per hour (the sound barrier at that altitude). Because of the secrecy of the project, the accomplishment was not announced until June 1948.
