EG-0084-02
The NACA X-1E was the last of the X-1 series of aircraft, and its construction benefited from the lessons of earlier research aircraft programs. This included the explosions which destroyed the X-1D and the X-1-3 research aircraft, the poor performance of the X-3, and the destruction of both X-2s.
In 1951, the Air Force expected to begin flights with the X-1D, while the NACA was to soon receive the X-1-3. Both aircraft could reach speeds in excess of Mach 2, but were lost in explosions before they were able to produce data. The X-1A and X-1B would not be delivered for two more years, leaving only the NACA’s X-1-2 (serial number 46-063) still flying. The Air Force had already retired the X-1-1 (serial number 46-062), giving it to the Smithsonian. Soon after, the NACA discovered that the high-pressure nitrogen spheres in the second X-1 were likely to fail due to metal fatigue. The aircraft made its 54th and final flight on Oct. 23, 1951.
At this juncture, the NACA decided to flight test the characteristics of very thin wings at transonic speeds. Accordingly, NACA engineers proposed the X-1-2 be modified with the new airfoil and a new turbopump fuel system (which eliminated the high-pressure nitrogen spheres)…Learn more