Facts summary and sources
Bell X-1: speed field: Mach 1.45 (Reported flight result). First flight: 1946. Unpowered and powered first flights occurred in 1946; 1947 is the first supersonic milestone.
This is a secondary compilation. A source-check date applies only to the listed claim, not to the whole page or its translation. A page update is not a source check.
Sources and check records
- NASA: American X-Vehicles, first-generation X-1 — First-generation maximum: Mach 1.45, about 960 mph; 157 flights during 1946–1951. [First-generation flight-test results, not later X-1 variants.] · Source checked for this claim: 2026-10-07
- NASA: First Generation X-1 — The first glide and powered flights occurred in 1946; the first supersonic flight was October 14, 1947. [First flight and sound-barrier milestone are separate events.] · Source checked for this claim: 2026-10-07
- Wikipedia reference · Source-check date not recorded
✈️ Full Specifications
| Designation | X-1 |
| Manufacturer | Bell Aircraft |
| Country | 🇺🇸 United States |
| First flight | 1946 |
| First-flight context | Unpowered and powered first flights occurred in 1946; 1947 is the first supersonic milestone. |
| Crew | 1 |
| Length | 9.45 m (31 ft) |
| Max Speed (Mach) | 1.45 |
| Speed evidence basis | Reported flight result |
| Max Speed | 1,545 km/h |
| Engine | XLR-11 rocket engine |
Overview
The Bell X-1 was the first crewed aircraft to exceed the speed of sound in level flight. On October 14, 1947, Captain Chuck Yeager piloted the X-1 named ‘Glamorous Glennis’ to Mach 1.06 at an altitude of 43,000 feet over the Mojave Desert, forever changing the course of aviation history.
Design & Development
Designed to resemble a .50 caliber bullet—known for its stability at supersonic speeds—the X-1 featured thin, unswept wings and a streamlined fuselage. It was powered by an XLR-11 rocket engine with four chambers producing 6,000 lbf of thrust. The aircraft was air-launched from a modified B-29 Superfortress at approximately 25,000 feet.
Operational History
The three original X-1 aircraft made 157 flights from 1946 to 1951. NASA records a highest speed of Mach 1.45 (about 960 mph) and a highest altitude of 69,000 feet for this first generation. Later X-1A, X-1B and X-1E aircraft continued the wider research program with different performance. The first glide and powered flights were in 1946; October 14, 1947 marks the sound-barrier flight, not the aircraft’s first flight. NASA X-vehicle inventory, first-generation X-1 entry.
Legacy
The original X-1 now hangs in the Smithsonian National Air and Space Museum alongside the Wright Flyer and Spirit of St. Louis—a testament to its place as one of the most important aircraft in history.
Armament & Weapons
The X-1 was a pure research aircraft and carried no weapons. Its sole purpose was to explore transonic and supersonic flight regimes. All available weight was dedicated to the XLR-11 rocket engine fuel (ethyl alcohol and liquid oxygen) and flight test instrumentation.
Video
Frequently Asked Questions
How fast is the Bell X-1?
NASA lists Mach 1.45 and about 960 mph (1,545 km/h) for the first-generation X-1. Its famous October 14, 1947 flight reached Mach 1.06; that milestone was not its eventual maximum speed.
Is the Bell X-1 still in service?
No. The three first-generation X-1 aircraft flew 157 times between 1946 and 1951. The original “Glamorous Glennis” is preserved at the Smithsonian National Air and Space Museum.
How many Bell X-1 aircraft were built?
Three X-1 aircraft were built by Bell Aircraft Corporation.
Who was the first pilot to break the sound barrier?
Captain Chuck Yeager broke the sound barrier on October 14, 1947, flying the X-1 nicknamed “Glamorous Glennis” over the Mojave Desert at an altitude of 43,000 feet.