During World War II, the world of aviation underwent an impressive technological revolution. Each time the aircraft were able to fly higher and faster. But pilots and engineers ran into the so-called ‘sound barrier’ over and over again. That is, the possibility of exceeding the speed at which sonic waves are transmitted through the air. Approximately 344 m / s at 20 ° C temperature, or what is the same, 1,238.4 km / h.