"Glamorous Glennis" suspended at Smithsonian NASM. This was the first aircraft to go supersonic on 14 Oct 1947, flown by Capt C. Yeager. The X-1 was dropped around 23,000 ft. by a modified B-29 flown by Maj R. Cardenas. After climb the flight plan was to reach Mach 0.97 but the sound barrier was crossed that day to attain a speed of Mach 1.06 after levelling off at 43,000 ft. The X-1 was powered by a 26.5 kN Reaction Motors XLR11-RM3 rocket engine with four combustion chambers burning LOX and ethyl alcohol. The combustion chambers could be turned on and off individually but not throttled.

Originally designated as X-1-2. Converted to an X-1E in order to pursue the goals originally set for the X-1D and X-1-3 which were lost to explosions in 1951. First flew in 1955. Assigned to NACA High-Speed Flight Research Station, later the High-Speed Flight Station at Edwards AFB, CA. Permanently grounded after its 26th flight in 1958, due to the discovery of structural cracks in the fuel tank wall. Later put on display at Edwards AFB.

The second X-1 airframe, later rebuilt to X-1E standard. Photo from: NASA

Rocket-powered air-launched supersonic research aircraft. Named after pilot Chuck Yeager's wife