The full length of the X-3 Stiletto just fits the frame during a visit to the newly opened X-planes hall of the National Museum of the USAF in Wright Patterson in 2016. It was first flown from Edwards AFB in 1952 and designed to test sustained flight at twice the speed of sound. It also explored the use of very short wings and titanium airframe construction. Because it was underpowered with an interim J34 engine, it failed to achieve the high speeds for which it was designed. By 1956 it had been transferred to this museum.

This is the only X-3, first flown from Edwards AFB in 1952 and designed to test sustained flight at twice the speed of sound. It also explored the use of very short wings and titanium airframe construction.. Because it was underpowered with an interim J34 engine, it failed to achieve the high speeds for which it was designed. By 1956 it had been transferred to the USAFM

The X-3 was designed for sustained Mach 2 flight, but could not even reach Mach 1. It did not have the intended engines. Its take-off speed was certainly high - 480 km/h (300 mph). Only the first of two examples, 49-2892, was completed and flown, for the first time in October 1952. The aircraft was handed over to NACA in August 1954, becoming NACA 892. Photo by: Loomis Dean / Life

Slide taken in outdoor aircraft display area at the original USAF Museum site. The X-3 was transferred to the museum in 1956, and is now on display inside the current museum. The X-3 never reached its potential due to underpowered engines, but it did contribute data on high speed stability issues. The X-3 wing design was used on both the Lockheed F-104 and the North American X-15.