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.