Constructed as a C-131B and taken on strength with the US Air Force with serial 53-7793 in 1955 it was used as a radar testbed. In 1966, the aircraft was transferred to Calspan, Buffalo (NY) and redesignated NC-131B. From December 1968 to 1970 it was converted to an NC-131H, its engines changed from piston radials to Allison 501-D-13 turbo-props, made its first flight as a Total Flight-In Simulator (TIFS) in 1970. After various projects it was handed over to Calspan as N793VS on 23 December 2003. To the USAF Museum in Wright-Patterson on 7 November 2008.