1947

44 years after the first twelve seconds

Bell X-1 Glamorous Glennis

Through the sound barrier

10 m · person 1.75 m · behind it, the A380 at the same scale

The story

Dropped from a B-29 bomber, lit the four rocket chambers and reached 1.06 at 13,000 m, the first piloted level flight faster than sound. The fuselage was shaped like a .50 calibre bullet, because bullets were known to stay stable above Mach 1.

Many believed the could not be passed: aircraft diving toward Mach 1 shook, lost control and sometimes broke up. Bell built the X-1 to find out, for the US Army Air Forces and the , the agency that became NASA. Its whole tailplane could be moved, and that gave Yeager back control of the pitch when shock waves made the elevator useless.

Two nights before the flight, Yeager broke two ribs falling from a horse. He told only his wife and the engineer Jack Ridley, who cut him a length of broom handle so he could lever the cockpit door shut. He named the aircraft after his wife, Glennis, and the flight was kept secret until June 1948.

How it works

How the X-1 was throttled: it wasn't. Each of the pilot's switches lights another chamber, so thrust climbs in four steps of about 6.7 kN, burning alcohol and liquid oxygen.
How the X-1 kept pitch control near Mach 1. Drag the speed up and a shock wave forms on the tailplane and slides back. By Mach 0.94 it sits on the elevator's hinge and the elevator goes dead, so a screw jack turns the whole tailplane on its pivot instead.
The whole aircraftDrag to turn it, and pinch to zoom. Pick a part to fly the camera to it.

Loading the 3D model…

Specifications

Top speed
1,540 km/h
Wingspan
8.5 m
Max weight
5,560 kg
Ceiling
21,900 m
Range
—
In 12 seconds
5.1 km
Power
XLR11 rocket, 27 kN
101001,00010,000 km/h

Where it flew

Over , California

Over Muroc Dry Lake, California. Muroc is now Edwards Air Force Base; the dry lakebed is unchanged. The simulator starts here, over today's ground and imagery of the place.

Fly it yourself

Take the Bell X-1 up in 3D, with its real weight, wing area and power.

You have 2½ minutes of rocket fuel. Climb and pass Mach 1.

On displayNational Air and Space Museum, Washington, D.C.

Where it sits in a century of speed

Top speed of every aircraft on the timeline, on a logarithmic scale, with this one marked.

101001,00010,000km/h1900192019401960198020002020 Mach 1 at altitudeWright FlyerBell X-1North American X-15ConcordeIngenuity
3/6

Formula 1 car · ≈ 370 km/h10 of 16 aircraft here are faster than a Formula 1 car (≈ 370 km/h).

All sixteen aircraft

  1. 1903Wright Flyer
  2. 1909Blériot XI
  3. 1917Sopwith Camel
  4. 1927Spirit of St. Louis
  5. 1936Douglas DC-3
  6. 1939Heinkel He 178
  7. 1947Bell X-1
  8. 1958Boeing 707
  9. 1964SR-71 Blackbird
  10. 1967North American X-15
  11. 1969Boeing 747
  12. 1976Concorde
  13. 1989Northrop B-2 Spirit
  14. 2007Airbus A380
  15. 2011Boeing 787 Dreamliner
  16. 2021Ingenuity
Back to the timeline

Airspeed km/h
0
Mach 0000°Altitude m
0
Climb 0 m/s
Throttle0%

WS throttle↑↓ pitch←→ rollC cameraM soundR restart