When Was the First Supersonic Flight?
Supersonic flight is one of the four speeds of flight. They are called the regimes of flight. The regimes of flight are subsonic, transonic, supersonic and hypersonic. Vehicles that fly at supersonic speeds are flying faster than the speed of sound. The speed of sound is about 768 miles per hour (1,236 kilometers per hour) at sea level. These speeds are referred to by Mach numbers. The Mach number is the ratio of the speed of the aircraft to the speed of sound. Flight that is faster than Mach 1 is supersonic. Supersonic includes speeds up to five times faster than the speed of sound, or Mach 5.
The first time a manned aircraft exceeded the speed of sound (Mach 1) on a level flight was on October 14, 1947. Air Force Capt. Charles E. “Chuck” Yeager of the United States Air Force flew America’s Bell X-1 rocket-propelled research aircraft 45,000 feet over Edwards Air Force Base, Muroc, California, at a speed of Mach 1.015 (about 770 miles an hour).
Capt. Charles E. “Chuck” Yeager became the first person to fly an aircraft faster than the speed of sound. Jackie Cochran was the first woman to break the sound barrier on May 18, 1953, in a Canadair Sabre, with Yeager as her wingman. Known as Glamorous Glennis, this aircraft was the first rocket-propelled aircraft in the world designed for research into high speed aerodynamics. It was a single-seated monoplane with an enclosed pressurized cabin lying flush to the surface.
In 1946 the X-1 underwent a series of tests during which it was released from a Boeing B-29 Superfortress in flight and allowed to glide to earth. The aircraft first flew under its own power after one such drop on December 9, 1946. But its first take-off under power did not take place until January 5, 1949. Glamorous Glennis is now in the National Air and Space Museum of the Smithsonian Institution, Washington, D.C.
The three main participants in the X-1 program won the National Aeronautics Association Collier Trophy in 1948 for their efforts. Honored at the White House by President Truman were Larry Bell for Bell Aircraft, Captain Yeager for piloting the flights, and John Stack for the contributions of the NACA.
The story of Yeager’s 14 October flight was leaked to a reporter from the magazine Aviation Week, and The Los Angeles Times featured the story as headline news in their 22 December issue. The magazine story was released on 20 December. The Air Force threatened legal action against the journalists who revealed the story, but none ever occurred. On 10 June 1948, Air Force Secretary Stuart Symington announced that the sound barrier had been repeatedly broken by two experimental airplanes.
On 5 January 1949, Yeager used Aircraft #46-062 to perform the only conventional (runway) launch of the X-1 program, attaining 23,000 ft (7,000 m) in 90 seconds.
The British Air Ministry signed an agreement with the United States to exchange all its high-speed research, data and designs and Bell Aircraft Company was given access to the drawings and research on the M.52, but the U.S. reneged on the agreement and no data was forthcoming in return. Bell’s supersonic design was still using a conventional tail and they were battling the problem of control.
They utilized the information to initiate work on the Bell X-1. The final version of the Bell X-1 was very similar in design to the original Miles M.52 version. Also featuring the all-moving tail, the XS-1 was later known as the X-1. It was in the X-1 that Chuck Yeager was credited with being the first person to break the sound barrier in level flight on October 14, 1947, flying at an altitude of 45,000 ft (13.7 km).
George Welch made a plausible but officially unverified claim to have broken the sound barrier on 1 October 1947, while flying an XP-86 Sabre. He also claimed to have repeated his supersonic flight on October 14, 1947, 30 minutes before Yeager broke the sound barrier in the Bell X-1. Although evidence from witnesses and instruments strongly imply that Welch achieved supersonic speed, the flights were not properly monitored and are not officially recognized. The XP-86 officially achieved supersonic speed on April 26, 1948.
On August 21, 1961, a Douglas DC-8-43 (registration N9604Z) exceeded Mach one in a controlled dive during a test flight at Edwards Air Force Base. The crew was William Magruder (pilot), Paul Patten (copilot), Joseph Tomich (flight engineer), and Richard H. Edwards (flight test engineer). This is the first and only supersonic flight by a civilian airliner, other than Concorde or the Tu-144.