Historic Aircraft: Bell X-1 Breaking the Sound Barrier
Ever since man first took to the skies in powered aircraft, pilots and aviation engineers have sought to overcome challenges and push perceived boundaries as technology developed. One of the much debated challenges back in the early 1940s was whether it was possible for an aircraft to travel fast enough to break the sound barrier. On October 14, 1947, legendary pilot Chuck Yeager proved it was indeed possible when he pushed the Bell X-1 he was flying to Mach 1.06 (1,100 km/h; 700 mph) going down in history as the first pilot to break the sound barrier.
Nicknamed Glamorous Glennis in honor of Yeager’s wife, the Bell X-1 was built by the Bell Aircraft Company under the direction of a joint supersonic research project run by the National Advisory Committee for Aeronautics, the US Army Forces and the US Air Force. The concept for the airplane was developed in 1944 and it was built the following year. The fuselage of the X-1 was shaped like a 0.5-calibre machine gun bullet for stability and the thin wings were designed to reduce drag. As it was only later discovered that the swept-wing design is more efficient for speed, the X-1’s wings were at a 90 degree angle to the fuselage. The pilot was seated inside a confined cockpit in the nose, behind a sloped, framed window, and the airplane was powered by a single XLR-11 engine running on liquid oxygen, alcohol and water.
On the historic sound barrier breaking flight, the supersonic Bell X-1 was drop-launched from a B-29 Superfortress bomber airplane at an altitude of 23,000 feet (7,000 meters), where it quickly climbed to its test altitude of 43,000 feet (13,000 meters) and proceeded to break the sound barrier before landing on a dry lake bed. In recognition of their achievement, the 1948 Collier Trophy was awarded jointly to Larry Bell of Bell Aircraft, Captain Charles “Chuck” Yeager, and John Stack of the National Advisory Committee for Aeronautics.
As the first in the so-called X-planes, the X-1 set the pattern for future projects, with data collected during its test flights providing essential information for later aircraft designs.