|The first aircraft in the world to break the sound barrier was the Bell X1. On the 14 October 1947 it reached 670mph at 42000feet (Mach 1.015). The X1 was launched by a Boeing B29 at 30000 feet, once released the rocket motor on the X1 was fired and it would begin it's ascent.|
Concept that the speed of sound, or sonic speed (about 1,220 kph/760 mph at sea level), constitutes a speed limit to flight through the atmosphere, since a badly designed aircraft suffers severe buffeting at near sonic speed owing to the formation of shock waves. US test pilot Chuck Yeager first flew through the `barrier' in 1947 in a Bell X-1 rocket plane.
Now, by careful design, such aircraft as Concorde can fly at supersonic speed with ease, though they create in their wake a sonic boom.