12 ft. 1 in.
5 ft. 2 in.
The X-43A Scramjet is the world's fastest and highest flying "air breathing" engine vehicle. It does not have a pilot.
X-43A Scramjet on nose of booster rocket
On November 16, 2004 the X-43A Scramjet was launched from a booster rocket from under the wing of a B-52. Launch altitude was 40,000 feet. The booster rocket lifted the aircraft to a maximum altitude of approximately 110,000 feet before its fuel was entirely expended. The X-43A Scramjet separated from the booster rocket and proceeded under its own power. The top speed reached by the X-43A Scramjet for about 11 seconds during this flight was Mach 10 (about 6,600 mph).
X-43A Scramjet separation from booster rocket
The vehicle was not designed for recovery, and it crashed in to the Pacific Ocean. This was the third and last in a series of flights for the X-43A Scramjet to gather aerodynamic data.
The project began in 1996 with the building of three drone aircraft. The two previous aircraft flew at speeds of about 4,620 mph.
The design of the front of the aircraft actually contributes to engine efficiency by channeling and compressing air entering the engine beneath the vehicle.
The X-43A Scramjet was a test vehicle with a lifting body and waverider design, where, rather than its wings providing lift, it is generated from the vehicle's fuselage. It was not a radio controlled aircraft. Its internal navigation systems provided full control of the vehicle during its entire flight.
Although future flights were planned using hydrocarbon based fuels, initial flights were hydrogen propelled.
On May 26, 2010 a similar vehicle, the X-51 WaveRider, achieved a top speed of about 3,500 mph with a duration of about 3 minutes 40 seconds.
It is hoped that scramjet powered, waverider type vehicles will some day be able to fly orbital missions efficiently carrying heavy payloads.