This article is about experimental aircraft. For the flight simulator, see X-Plane.

The X-planes are a series of experimental United States aircraft (and some rockets) used for testing of new technologies and usually kept highly secret during development.

The first of these, the Bell X-1, became well-known as the first plane to break the sound barrier, which it did in 1947. Later X-planes yielded important research results, but only the North American X-15 rocket plane of the early 1960s achieved comparable fame. X-planes 7 through 12 were actually missiles, and some other vehicles were unpiloted. Most X-planes are not expected to ever go into full-scale production, and usually only a few are produced. One exception is the Lockheed Martin X-35, which competed against the Boeing X-32 to become the Joint Strike Fighter.

X-plane projects are still underway as of 2004.

• Bell X-1 - rocket plane
• Bell X-2 - swept wing
• Douglas X-3 Stiletto
• Northrop X-4 Bantam - swept wing, semi-tailless
• Bell X-5 - in-flight wing sweeping
• Convair X-6 - nuclear-powered
• Lockheed X-7 - ramjet missile
• Aerojet General X-8
• Bell X-9 Shrike
• North American X-10
• Convair X-11
• Convair X-12
• Ryan X-13 Vertijet
• Bell X-14
• North American X-15
• Bell X-16
• Lockheed X-17
• Hiller X-18
• Curtiss-Wright X-19
• Boeing X-20 Dyna-Soar
• Northrop X-21
• Bell X-22
• Martin-Marietta X-23
• Martin-Marietta X-24
• Bensen X-25
• Schweizer X-26 Frigate
• Lockheed X-27
• Pereira X-28 Sea Skimmer
• Grumman X-29
• Rockwell X-30
• Rockwell-MBB X-31
• Boeing X-32
• Lockheed Martin X-33
• Orbital Sciences X-34
• Lockheed Martin X-35
• McDonnell Douglas X-36
• Boeing X-37 - Future-X
• X-38
• X-39 - unused designation reserved for Future Aircraft Technology Enhancements programme
• Boeing X-40
• X-41 Common Aero Vehicle
• X-42 Pop-Up Upper Stage
• Boeing X-43
• Lockheed Martin X-44 MANTA
• Boeing X-45 UCAV
• Boeing X-46
• Northrop Grumman X-47 Pegasus - UCAV
• Boeing X-48 - blended wing body
• Sikorsky Piasecki X-49
• Boeing X-50 - canard rotor/wing

See also

• Experimental aircraft
• List of experimental aircraft
• List of military aircraft of the United States

Reference

• Jay Miller , The X-Planes: X-1 to X-45 (Motorbooks International , 2001)

External link

• Early X-planes

• American X-Vehicles: An Inventory X-1 to X-50, SP-2000-4531 - June 2003; NASA online PDF Monograph