Breaking the Sound Barrier: Mach 1, 1947
1947 · event
On 14 October 1947, high above the dry lake bed at Muroc in the California desert, a small orange aircraft was dropped from the belly of a bomber, lit its rocket engine and climbed. At about thirteen thousand metres the needle of the machmeter jumped and the buffeting stopped. On the ground observers heard a sound like distant thunder. Chuck Yeager, a twenty four year old test pilot, had flown the Bell X-1 faster than sound, the first person to do so in level flight.
Engineers had watched aircraft shake themselves apart as they approached the speed of sound during the war, and the phrase sound barrier had come to suggest a wall in the air. The X-1 was built to go through it. Its fuselage was shaped like a rifle bullet, it had thin straight wings and a movable tail plane, and it burned alcohol and liquid oxygen for less than three minutes of powered flight.
Two nights before, Yeager had broken two ribs falling from a horse. He said nothing, because he would have been replaced, and a fellow pilot cut him a length of broom handle so he could reach across and close the hatch with his left arm. The flight was classified, and the world only learned of it in the middle of 1948.
Supersonic flight moved quickly from a laboratory result to routine engineering. Within a decade fighters flew at twice the speed of sound, and within twenty years an airliner was being built to carry passengers past it. The X-1 hangs today in the National Air and Space Museum in Washington, and the term sound barrier survives as a description of something that was never really a wall.