The Douglas X-3 Stiletto was a 1950s experimental jet aircraft built by the Douglas Aircraft Company with a narrow fuselage and a long tapered nose. Its main goal was to look into the design characteristics of an airplane capable of sustained supersonic speeds, which included the first usage of titanium in critical airframe components.
The Douglas X-3 Stiletto was the sleekest of the early experimental planes, but its scientific achievements were not as expected. The X-3 was meant to reach a top speed of over 2,000 m.p.h., but it was woefully underpowered for the job and could not even achieve Mach 1 in level flight.
Despite the failure of the research aircraft, Lockheed designers used data from the X-3 experiments to develop the Lockheed F-104 Starfighter, a successful Mach 2 fighter with a trapezoidal wing shape.
