Supersonic
Any speed over the speed of sound, which is approximately 343 m/s or 761 mph or 1,225 km/h at sea level, is said to be supersonic. Many modern fighter aircraft are supersonic. The Concorde was a supersonic passenger aircraft, but, since its final retirement flight on November 26 2003, there is no supersonic passenger aircraft in service. Speeds greater than 5 times the speed of sound are sometimes referred to as hypersonic.
Chuck Yeager was the first man to break the sound barrier on October 14 1947, flying the experimental Bell X-1 at Mach 1 at an altitude of 45,000 feet (13.7 km).
A team led by Richard Noble and driver Andy Green became the first to break the sound barrier in a land vehicle October 15 1997, almost exactly 50 years after Yeager's flight.
Hans Guido Mutke claimed to have broken the sound barrier before Yeager, on April 9 1945 in a Messerschmitt Me 262. However, this claim is disputed by most experts and lacks a scientific foundation.
See also
de:Überschallflug es:Velocidad supersónica it:Regime supersonico sv:Överljudshastighet