The wingtips were upturned to form fins. The edges of the wing and fins had a blck tile covering, while the rest of the fuselage was white. The rear fuselage had a raised area with a black line extending down it. Some witnesses reported seeing a long-span canard near the nose. It was said to be about 200 feet long.
Nothing is known, however, about the aircraft's propulsion system.
Operating on a different principle then conventional ramjets, PDWEs dont't continuously burn kerosene, but detonate fuel as it starts to leave the combustion chamber. The most probable fuel for PDWEs would be cryogenic liquid methane, which could also act as a structural coolant. The unidentified aircraft flew past the 747 about 500-1000 feet below it at high supersonic speed. It has been reported that the spaceplane is codenamed Brilliant Buzzard or Blue Eyes . Despite the X-24C being officially scrapped in 1977 and NASA and the USAF apparently unable to produce enough money to build prototypes, Historian Rene Francillon, in a survey of Lockheed aircraft published in 1982, reported that Lockheed had already flown an experimental aircraft capable of sustained flight at Mach 6.