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