This aircraft is the No. 2 aircraft and was transferred to the National Air Museum shortly after the program ended. It was restored by the Western Museum of Flight, Hawthorne, California.
Northrop X-4
The X-4 was developed to study flight characteristics
of swept wing semi-tailless aircraft at transonic speeds (about
Mach .85). Northrop built two
X-4s. The No. 1 aircraft was first flown by Northrop on December
16, 1948, and the second X-4 made its initial flight on June 7,
1949.