Lots of air force planes can fly past mach (pronounced mock) 1, such as the F/A-18, and F-22. But what is mach 1? Mach 1 is measurement of speed, 767.269 miles per hour, in fact. But whats so important about this number? It’s the exact speed that sound travels at.
The Bell X-1 experimental aircraft was launched from the bomb bay of a B-29 heavy bomber aircraft at subsonic speeds, (below the sound barrier, which is at mach 1). As the Bell X-1 moves, it disturbed the air around it, like any other moving thing would, sending out pressure waves that move at mach 1. When the Bell X-1 reaches mach 1, it catches up with it own pressure waves, and they accumulate into a shock wave. The plane is currently at mach 1, and struggling to break through the sound barrier. Finally, the plan breaches the sound barrier and fly’s above mach 1.
Why was the Bell X-1 launched? During WWII, the best fighters such as Mustangs and Spitfires hit a “sonic wall”, pilots had difficulty handling planes. The reason was that planes reached mach 1 but couldn’t get past it, just shuttering at top speed. To break the sound barrier was suddenly an international race, and some planes shuttered themselves apart. But finally on the historical day of October 14, 1947, Charles Yeager got into the Bell X-1 risking death, like so many others attempting this goal, as there were no ejection seats or emergency exits aboard. Just him and fate.