List of experimental aircraft - Definition

This is a list of experimental aircraft. Most aircraft are marked as experimental when they are first designed, so this list will focus on notable vehicles that never went into production and experimental variations of vehicles that were produced. The X-plane series of experimental aircraft is one of the most well-known groups of such planes.

X-planes

• Bell X-1
• Bell X-2
• Douglas X-3 Stiletto
• Northrop X-4 Bantam
• Bell X-5
• Convair X-6
• Lockheed X-7
• X-8 - missile
• Bell X-9 Shrike
• North American X-10
• X-11 - missile
• 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
• Scaled Composites X-38
• X-39 - unused designation reserved for Future Aircraft Technology Enhancements programme
• Boeing X-40
• X-41 - classified programme - re-entry vehicle.
• X-42 - classified programme - rocket stage
• Boeing X-43
• Lockheed Martin X-44 MANTA
• Boeing X-45 UCAV
• Boeing X-46
• Northrop Grumman X-47 Pegasus
• Boeing X-48
• Sikorsky Piasecki X-49
• Boeing X-50

XB series

• North American XB-70 Valkyrie

Others

• Boeing Bird of Prey
• Convair XF-92
• Douglas D-588-I Skystreak
• Douglas D-588-II Skyrocket
• NASA M2-F1
• Goodyear Inflatoplane
• Lockheed Have Blue
• Northrop HL-10
• Northrop M2-F2
• Northrop M2-F3
• Northrop Tacit Blue
• Scaled Composites
  • Boomerang
  • Proteus