Breaking Sound Barriers: 7 Fun Facts

Crossing the sound barrier, also known as exceeding Mach 1, is the point at which an aircraft equals and surpasses the speed of sound. As an aircraft approaches the barrier, increases in drag and other effects make it difficult to continue accelerating. At sea level and 68 degrees Fahrenheit, the speed of sound is approximately 767 mph (343 meters per second).

Most of us are familiar with the achievements of Yeager, the first pilot to officially break the sound barrier in 1947 in the Bell X-1 Glamorous Glennis. But what else do you know about the fastest pilots in history? 

Here are seven fun facts about sound barrier-busting flights, shedding light on the challenges and triumphs above Mach 1. 

Breaking the sound barrier creates a shock wave known as a “sonic boom.” This occurs when an aircraft moves faster than the speed of sound, resulting in a sudden release of pressure waves.

The first supersonic passenger aircraft, Concorde, entered commercial service in 1976. It could reach speeds of Mach 2.04 (around 1,354 mph or 2,170 kph) and complete a transatlantic flight in just more than three hours.

Jacqueline Cochran became the first woman to break the sound barrier on May 18, 1953, flying the Sabre 3 at Rogers Dry Lake, California. Cochran had celebrated her 48th birthday the week before.

Pilots flying at supersonic speeds experience a phenomenon known as "Mach tuck" or "compressibility." Changing airflow over the wings alters the wings’ center of pressure, causing the aircraft to pitch downward. Special measures are taken to mitigate this effect, like enlarging the horizontal stabilizer or moving fuel tanks on the fuselage.

The term "sound barrier" is somewhat misleading because there is no physical barrier at the speed of sound. The term is a holdover from early attempts that found it difficult to overcome the increased aerodynamic drag and other effects as aircraft approached Mach speeds.

In 2012, Austrian skydiver Felix Baumgartner jumped from a height of approximately 24 miles, reaching a top speed of Mach 1.25 during his free-fall skydive.

The world's fastest manned aircraft, the Lockheed SR-71 Blackbird, is capable of sustained speeds exceeding Mach 3 (approximately 2,300 mph). It owns the record for the fastest air-breathing, manned, powered aircraft.