First Person to Fly Faster Than Sound

USAF Brigadier General Charles Yeager

The Bell X-1 in flight.

On February 13, 1923, Yeager was born in Myra, West Virginia, about 38 miles (61 km) west-southwest of Charleston. He served in the United States Air Force from 1941 - 1975, retiring as a Brigadier General. Yeager died on December 07, 2020, at age 97.

The aircraft Yeager used to accomplish this feat of breaking the sound barrier was the Bell X-1 aircraft. First, it was flown to 25,000 feet (7,620 meters) by a B-29 airplane; then, it was released through the bomb bay and then very rapidly increased its altitude to 45,000 feet (13,716 meters) and exceeded 662 miles per hour (1,065 km/h).

For many years, it seemed impossible to fly faster than the speed of sound due to what is known as "transonic drag rise." It would end up tearing any aircraft apart. Then, on October 14, 1947, Yeager achieved the unimaginable over Rogers Dry Lake in Southern California. At an altitude of 45,000 feet (13,716 meters), he accelerated to a speed beyond 662 miles per hour (1,065 km/h), the speed of sound at that altitude.

The speed of sound is considerably higher at lower altitudes, such as at sea level. At sea level, the speed of sound on a 68°F (20°C) day would be about 767 mph (1,235 km/h). Due to air temperature and the composition of the air rather than altitude, the speed of sound varies. However, as one rises in altitude, the air temperature drops consistently at a rate of 3.56°F (1.98°C) per 1,000 feet (304.8 meters) rise from sea level to approximately 36,090 feet (11,000 meters). This decrease in air temperature as altitude increases is called the lapse rate. From 36,090 feet (11,000 meters) to 65,620 feet (19,818 meters), the constant temperature is -69.7°F (-56.5°C). The temperature rises steadily due to ozone above this altitude to approximately 27 miles (43 km). It is in this area that ozone is most abundant.