Bell X-1



The Bell X-1 was the first of a group of aircraft designed to investigate the dynamics of Supersonic flight.

Mission
The X-1 was designed to explore, in full-scale, the dynamic characteristics of aircraft flying at or greater than the speed of sound. Of primary importance was its ability to safely explore the transonic speed envelope wherein an object transitions from subsonic to supersonic flight. The affects of supersonic flight on stability and control were perhaps the two most important research objectives at the beginning of the program. Later, dynamic structural, propulsion, and physiological phenomena became primary research objectives.

Initiated
The official X-1 contract (W33-038-ac-9183) was signed on March 16,1945. Other work had been undertaken beginning in December of 1943. Ancillary research leading up to the X-1 program had started during the mid-1930s.. Air Force serial numbers assigned were 46-062, 46-063, and 46-064. Initially, these aircraft were designated XS-1. During the course of development and preliminary flight test, the "S" ("Supersonic") designator was dropped.

History
The X-1 was the first aircraft to ﬂy solely with the for "experimental", designation. The program had been born during World War ll when aerodynamicists and structural engineers became concerned that compressibility phenomena could become a major obstacle to high-speed aircraft performance.

Unfortunately, contemporary wind tunnels, as research tools, were of little use at speeds between 0.75 and 1.3 Mach. Problems with "transonic choking", a phenomenon caused by test model shock waves reflecting off tunnel walls and back onto the models, effectively curtailed scientific studies of aerodynamic flow characteristics in this critical speed regime. Transonic choking eventually was eliminated (through the development of slotted tunnel walls) after a multi-year NACA-Langley-sponsored research program. However, this did not occur until after X-1 flight testing got under way in 1946.

Throughout 1944, design and engineering studies for a proposed compressibility research aircraft were conducted by the NACA, the Air Force, and the Navy. The objective was to determine the most sensible and expedient means of development.

Perhaps the most critical personality in the US transonic aircraft program was Ezra Kotcher. Working as an engineer at Wright Field during 1939, Kotcher proposed that the Army Air Corps sponsor the development of a full-scale, manned transonic research aircraft. His suggestion was not given serious consideration at the time, but four years later, as World War ll slowly came to a bitter end and the insidious effects of compressibility became impossible to ignore, strong interest in transonic flight phenomena finally led to much-needed government and industry backing.

Kotcher, during early 1944, renewed his work on transonic aircraft and initiated work on a study that compared the merits of rocket versus jet (and ramjet) propulsion. He eventually concluded that the rocket-propelled research aircraft offered superior performance and greater versatility.

With Kotcher looking over their shoulders, an engineering team at Wright Field, consisting of Capt F D Orazio and Capt G W Bailey, proceeded to design an aircraft that, it was hoped, would be suitable for exploring the transonic speed envelope. Kotcher took the Orazio and Bailey summary and presented it to several Army Air Force and NACA engineering teams. The latter needed little convincing that the merits of the

Related Aircraft

 * X-1A
 * X-1B
 * X-1C
 * X-1D
 * X-1E