The product of a joint NACA/U.S. Navy project to explore transonic and supersonic flight, Douglas' D-558 design incorporated three phases: jet propulsion, rocket/jet combination, and design for a combat aircraft. Six of the new aircraft were ordered to conduct the first phase, incorporating various inlet configurations. Only three were built, however, and the rocket/jet phase was scrapped. The D-558-1 Skystreak on display, Bureau Number 37970, set a speed record of 641 mph at Edwards Air Force Base on 20 August 1947.
Brilliantly painted, the D-558-1s were first nicknamed "Crimson Test Tubes" until NACA had them repainted white to improve optical tracking and photography. Designed to explore transonic and supersonic flight, the D-558-1s were part of the early test plane era that flourished during the Cold War.
The D-558-1 was designed to withstand up to 18 Gs in order to explore the as yet unknown aspects of transonic flight. This led to the cockpit hood being designed to separate so that the pilot could bail out in an emergency. The fuselage was constructed of magnesium alloys, mated to wings of more conventional aluminum alloys. Bureau Number 37970, the aircraft displayed in the Museum, made its maiden flight 14 April 1947 at what is now Edwards Air Force Base. On 20 August, Navy test pilot Turner Caldwell established a new world speed record of 641 mph, eclipsing the unofficial record of 623.8 mph set in 1941 by a German Me 163 Komet. Caldwell's record lasted a mere five days; Marine Corps ace and test pilot Marion Carl, after urging technicians to "tweak" the J-35 engine a bit, managed to add 10 mph to the record while flying D-558-1 Bureau Number 39171. In turn, Carl's record fell on 14 October 1947, as Air Force Captain Chuck Yeager pushed the Bell X-1 to just over Mach 1, the first to officially break the sound barrier.
In all, the three D-558-1s made 228 flights, at one point reaching Mach 0.99 in level flight.