Bell X-1 (mock-up)

The Bell X-1, (originally the XS-1) was a joint NACA-U.S. Army Air Forces, secret supersonic research project built by Bell Aircraft. Conceived in 1944 and designed and built in 1945, it was the first aircraft to intentionally exceed the speed of sound in controlled, level flight. The aircraft conceptually was a “bullet with wings,” shaped to resemble a .50 caliber machine gun bullet (a projectile known to be stable at supersonic speeds.)

The aircraft was powered by a liquid-propellant rocket system featuring a four-chamber motor burning liquid oxygen and ethyl alcohol diluted with water, delivered from separate tanks pressurized with nitrogen. The rocket thrust was activated by the pilot incrementally by firing one or more chambers at a time.

Following a series of administrative issues with the Bell, the Army Air Force took over the flight test program, naming then Capt. Chuck Yeager as pilot and as every aviation buff knows, he would go on and ultimately proceed in smashing the sound barrier.

Launched from the bomb-bay of a modified B-29 flown by USAF Gen. Robert Cardenas, ret., it was on 14 October 1947, flight number 50, when the X-1 first flew supersonic reaching Mach 1.06 (807.2 mph). The huge supersonic boom over Muroc Lake that day announced the beginning of a new era of flight.


Length: 30 ft. 11 in. (9.4 m)
Wingspan: 28 ft. (8.5 m)
Height: 10 ft. (3.3 m)
Wing Area: 130 ft. (12 m)
Weight (Empty): 7,000 lb. (3,175 kg)
Weight (Loaded): 12,225 lb. (5,545 kg)
Max Takeoff Weight: 12,250 lb. (5,556 kg)
Power Plant: 1 X Reaction MotorsXLR-11-RM3 liquid fuel rocket 6,000 lbf. (1,500 lbf. per chamber) (26.7 kN)
Max Speed: 957 mph (Mach 1.26)
Range: 5 min. (powered endurance)
Service Ceiling: 71,900 ft. (21,900 m)
Wing Loading: 94 lb./ft. (463 kg/m)
Trust/Weight: 0.49

San Diego Air & Space Museum

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