Sound barrier

Bell X-1 Broke sound barrier
Bell X-2 Starbuster Investigated Mach 2-3 flight
Douglas X-3 Stiletto First use of titanium in major airframe components
Northrop X-4 Bantam Tailless aircraft prototype
Bell X-5 First variable-swept wing aircraft ...

Compressibility effects are most important in transonic flows and lead to the early belief in a sound barrier. Flight faster than sound was thought to be impossible.

When a plane travels faster than this speed it is breaking the sound barrier.

When you do travel greater then Mach one you break the sound barrier and the air around the plane starts to form shock waves. A shock wave is an abrupt pressure difference caused by the compression of air by the aircraft moving forward.

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).

Air Force fighters, including the F-100, the first to break the sound barrier without going into a dive. Eight such engines powered the B-52 bomber. Commercial airliners-the Boeing 707, the Douglas DC-8-flew with it.

The aircraft also featured an all-moving tailplane that allowed it to pass through the sound barrier safely. The pattern shape was followed to the point of removing a canopy.

See also: Speed, Aircraft, Flight, Supersonic, Aviation