The X-1D (48-1386), the first of the second generation of supersonic rocket planes produced by Bell Aircraft Corporation arrived at Edwards Air Force Base in July 1951,suspended from the bomb bay of a Boeing EB-50A (46-006). It was to be used for heat transfer research. The X-1D was equipped with a new low-pressure fuel system, a slightly increased fuel capacity, and minor changes in cockpit instrumentation.

On 24 July, with Bell company test pilot Jean Ziegler at the controls, the X-1D was launched over Rogers Dry Lake on what was to become the only successful flight of its career. The unpowered glide was completed after a nine-minute descent, but upon landing, the nose gear failed and the aircraft slid ungracefully to a stop. Repairs took several weeks to complete and a second flight was scheduled for mid-August.