This is a list of experimental aircraft. Most aircraft are marked as experimental when they are first designed, whether or not they are later produced. This list will focus on notable vehicles that never went into production and experimental variations of vehicles that were produced.

For U.S. designs this list will focus primarily on those aircraft that carried the "X" series designation or carried the "X" series designation as a prefix to a prototype, preproduction, or test aircraft.

Contents 1 U.S. "X" designations 1.1 Purely-experimental designs 1.2 XA series 1.3 XB series 1.4 XC Series 1.5 XF Series 1.6 XP Series 1.7 Others 2 U.S. Navy "X" designations 3 U.S. non-"X" designations 4 Canada 5 United Kingdom 6 Brazil-Argentina 7 Germany 8 Russia 9 People's Republic of China 10 Others 11 See also 12 References

[edit] U.S. "X" designations

[edit] Purely-experimental designs

• Bell X-1 Broke sound barrier
• Bell X-2 Starbuster Investigated Mach 2-3 flight
• Douglas X-3 Stiletto First use of titanium in major airframe components
• Northrop X-4 Bantam Tailless aircraft prototype
• Bell X-5 First variable-swept wing aircraft
• Convair X-6 Nuclear-powered aircraft
• Lockheed X-7 "Flying Stove Pipe" ramjet
• Aerojet General X-8 Sounding rocket (became Aerobee)
• Bell X-9 Shrike Guided missile
• North American X-10 Unmanned missile demonstrator
• Convair X-11 1-engine missile testbed for Atlas
• Convair X-12 3-engine missile testbed for Atlas
• Ryan X-13 Vertijet Delta wing VTOL jet
• Bell X-14 Conventional wing VTOL jet, pioneered thrust vectoring
• North American X-15 Mach 6 rocket plane
• Bell X-16 High altitude reconnaissance jet (only mockup built)
• Lockheed X-17 Rocket testing high mach re-entry
• Hiller X-18 Tiltwing STOVL cargo aircraft
• Curtiss-Wright X-19 VTOL tiltrotor propellers
• X-20 Dyna-Soar Spaceplane program (cancelled)
• Northrop X-21 Aircraft testing laminar flow wings
• Bell X-22 V/STOL ducted fan propellers
• Martin Marietta X-23 Prime Small lifting body; tested re-entry
• Martin-Marietta X-24 Tested lifting body shapes
• Bensen X-25 Single-seat autogyro
• Schweizer X-26 Frigate Sailplane
• Lockheed X-27 Lancer Proposed high-performance research aircraft (only mockup built)
• Pereira X-28 Sea Skimmer Single-seat flying boat
• Grumman X-29 Forward-swept wing; composites and fly-by-wire
• Rockwell X-30 National Aero-Space Plane Single-stage-to-orbit spacecraft (cancelled)
• Rockwell-MBB X-31 Enhanced Fighter Maneuverability (thrust vectoring)
• Boeing X-32 Joint Strike Fighter Program entry (lost to X-35)
• Lockheed Martin X-33 Unmanned sub-scale demonstrator for VentureStar spacecraft
• Orbital Sciences X-34 Reusable Launch Vehicle testbed (only unpowered prototype built)
• Lockheed Martin X-35 Joint Strike Fighter Program entry winner; became F-35 Lightning II
• McDonnell Douglas X-36 Tailless fighter research agility aircraft
• Boeing X-37 Reusable robotic spaceplane (classified)
• NASA X-38 Crew return vehicle for International Space Station (cancelled after tests)
• X-39 Reserved for USAF/DARPA program use
• Boeing X-40 Space Maneuver Vehicle Tested X-37 guidance and glide characteristics
• X-41 Common Aero Vehicle Maneuvering re-entry vehicle (classified)
• X-42 Pop-Up Upper Stage Rocket upper stage (classified)
• NASA X-43 Hyper-X Hypersonic scramjet
• Lockheed Martin X-44 MANTA Multi-axis no-tail aircraft concept design
• Boeing X-45 Unmanned combat air vehicle
• Boeing X-46 Unmanned combat air vehicle (proposed, never built)
• Northrop Grumman X-47 Pegasus Composite unmanned combat air vehicle
• X-48 Blended wing body aircraft
• Sikorsky Piasecki X-49 Speedhawk Vectored thrust ducted helicopter with lifting wings
• Boeing X-50 Dragonfly Gyrodyne unmanned aerial vehicle
• Boeing X-51 Mach 7 scramjet
• X-52 designation not used
• X-53 Active Aeroelastic Wing (AAW) flight demonstrator
• Lockheed Martin X-55 Advanced Composite Cargo Aircraft

[edit] XA series

Prototype or experimental attack aircraft:

• Stearman XA-21
• Douglas XA-26
• Douglas XA-26A
• Douglas XA-26B
• Vultee XA-31A
• Vultee XA-31B
• Vultee XA-31C
• Brewster XA-32
• Brewster XA-32A
• Beech XA-38 Grizzly
• Vultee XA-41

[edit] XB series

Prototype or experimental bomber aircraft:

• North American XB-25E
• North American XB-25F
• North American XB-25G
• Martin XB-26H
• Martin XB-27D
• Martin XB-27
• North American XB-28
• Boeing XB-29
• Lockheed XB-30
• Douglas XB-31
• Consolidated XB-32 Dominator
• Martin XB-33
• Martin XB-33A Super Marauder
• XB-34- not used; see B-34 Lexington
• Northrop XB-35
• Convair XB-36
• XB-37 - not used; see B-37
• Boeing/Lockheed Vega XB-38
• Boeing XB-39
• Boeing/Lockheed Vega XB-40
• Consolidated XB-41
• Douglas XB-42 Mixmaster
• Douglas XB-43 Jetmaster
• Boeing/Pratt & Whitney XB-44
• North American XB-45 Tornado
• Convair XB-46
• Boeing XB-47 Stratojet
• Martin XB-48
• Northrop XB-49
• Martin XB-51
• Boeing XB-52
• Convair XB-53
• Boeing XB-55
• Convair XB-58 Hustler
• Boeing XB-59
• Convair XB-60
• Martin XB-68
• North American XB-70 Valkyrie

[edit] XC Series

• LTV XC-142
• Convair XC-99

[edit] XF Series

This series covers post-World War II fighter development when the newly independent USAF changed the "P" pursuit designation to "F" for fighter.

• Convair XF-81
• Bell XF-83
• Republic XF-84H "Thunderscreech" - conversion of 2 F-84 Thunderjets to turboprop with supersonic propellor
• McDonnell XF-85 Goblin
• Curtiss XF-87 Blackhawk
• McDonnell XF-88 Voodoo
• Northrop XF-89 Scorpion
• Lockheed XF-90
• Republic XF-91 Thunderceptor
• Convair XF-92 Dart
• Republic XF-103 Thunderwarrior
• Lockheed XF-104
• North American XF-108 Rapier
• Bell XF-109

[edit] XP Series

This series covers fighter development up to the end of World War II. In 1947 the newly independent USAF changed the "P" pursuit designation to "F" for fighter.

• Boeing XP-4
• Boeing XP-7
• Boeing XP-8
• Boeing XP-9
• Curtiss XP-10
• Curtiss XP-11
• Thomas-Morse XP-13 Viper
• Curtiss XP-14
• Boeing XP-15
• Curtiss XP-17
• Curtiss XP-18
• Curtiss XP-19
• Curtiss XP-21 Hawk
• Curtiss XP-22 Hawk
• Curtiss XP-23 Hawk
• Curtiss XP-31 Swift
• Boeing XP-32
• Consolidated XP-33
• Wedell-Williams XP-34
• Seversky XP-41
• Curtiss XP-42
• Bell XP-45
• Curtiss XP-46
• Douglas XP-48
• Lockheed XP-49
• Grumman XP-50 Skyrocket
• North American XP-51 Mustang
• Bell XP-52
• Curtiss XP-53
• Vultee XP-54 Swoose Goose
• Curtiss XP-55 Ascender
• Northrop XP-56 Black Bullet
• Tucker XP-57
• Lockheed XP-58 Chain Lightning
• Bell XP-59 Airacomet
• Curtiss XP-60
• Curtiss XP-62
• Grumman XP-65
• McDonnell XP-67 Bat
• Vultee XP-68 Tornado
• Republic XP-69
• Curtiss XP-71
• Republic XP-72
• Hughes XP-73
• Bell XP-76
• Bell XP-77
• North American XP-78; redesignated XP-51B
• Northrop XP-79 Flying Ram

[edit] Others

• Bell XV-15 "Tiltrotor" - a VTOL aircraft with convertible turboprops that permitted it to take off and land like a helicopter, but fly like a conventional airplane. The concept was eventually implemented as the V-22 Osprey.

• The Silent Aircraft eXperimental Design (SAX-40) was an aircraft built under the Silent Aircraft Initiative, conducted by Cambridge-MIT is studying a range of technologies.

• ALTUS, Pathfinder and Helios were experimental aircraft under NASA's Environmental Research Aircraft and Sensor Technology program

[edit] U.S. Navy "X" designations

• Boeing XF8B
• Curtiss XF14C - Curtiss
• XF5F Skyrocket - Grumman
• XF10F Jaguar - Grumman
• Bell XFL Airabonita
• XF3L - Bell
• Ryan XF2R
• Chance Vought XF5U
• Lockheed XFV
• Convair XFY-1
• Convair XF2Y-1 Sea Dart

[edit] U.S. non-"X" designations

• AstroFlight
  • AstroFlight Sunrise
• Boeing
  • Boeing Bird of Prey
  • Boeing Skyfox
• Douglas D-558-I Skystreak
• Douglas D-558-II Skyrocket
• FALCON
• Goodyear Inflatoplane
• Lockheed Have Blue
• Lockheed P-175 Polecat
• NASA:
  • NASA M2-F1
  • NASA AD-1 Oblique Wing
• Northrop
  • Northrop HL-10
  • Northrop M2-F2
  • Northrop M2-F3
  • Northrop Tacit Blue
• Rockwell
  • HiMAT
• Rotary Rocket
  • Roton ATV
• Scaled Composites
  • Boomerang
  • Proteus

[edit] Canada

Research Aircraft and prototypes.

• Avro Canada CF-105 Arrow
• Avro Canada Avrocar
• Birdman Project 102
• Canadair CL-84 "Dynavert"

[edit] United Kingdom

Includes research aircraft, private company projects and prototypes produced in competition for Ministry of Defence contracts.

• Armstrong Whitworth A.W.52
• Avro
  • Avro 707
• BAC 221 - modified fairey Delta 2 for high speed delta research
• Blackburn B-20
• Boulton & Paul and Boulton Paul
  • Boulton Paul P.6 - used for wing research
  • Boulton Paul P.111
  • Boulton Paul P.120
• Bristol Aircraft Ltd
  • Bristol 188
  • Bristol Brabazon
• British Aerospace EAP
• De Bruyne Snark - plywood low weight stressed skin construction
• de Havilland Swallow - swept wing handling up to supersonice speeds
• English Electric P1A
• Fairey
  • Fairey Delta 1
  • Fairey Delta 2
  • Fairey Rotodyne
• Folland Fo.108 "Frightful" - engine test bed
• General Aircraft GAL.56
• Gloster E.28/39 - early jet engine research
• Hafner Rotabuggy - autogyro/jeep hybrid
• Handley Page
  • Handley Page Manx - tailess
  • Handley Page HP.88 - supporting development of Handley Page Victor
  • Handley Page HP.115 - low speed delta wing research
• Hawker
  • Hawker P.V.4 - unsuccessful tender for government contract
  • Hawker Hotspur - unsuccessful tender for government contract
  • Hawker P.1072
  • Hawker P.1052
  • Hawker P.1081
  • Hawker P.1127 - supersonic V/STOl fighter
• Hunting
  • Hunting H.126 - blown flap research
• Miles
  • Miles Libellula - tandem wing fighter and bomber designs
  • Miles M.30 - blended wing body design
  • Miles M.52 - supersonic research
• Saunders Roe
  • Saunders-Roe SR.A/1 - jet powered flying boat fighter
  • Saunders-Roe SR.53 - mixed rocket/jet propulsion interceptor
  • Saunders-Roe SR.177 - mixed rocket/jet propulsion interceptor
• Short Brothers
  • Short Shetland
  • Short Sperrin
  • Short SB.1 - tailess glider for isoclininc wing research
  • Short SB5 - prove/develop wing profile of English Electric Lightning
  • Short Sherpa
  • Short SC.1 - vtol research
• TSR-2
• Westland-Hill Pterodactyl

[edit] Brazil-Argentina

• Embraer/FMA CBA 123 Vector^[1]

[edit] Germany

• Arthur Sack A.S.6
• Blohm & Voss P.178
• DFS 194
• DFS 346
• Dornier Do 212
• Dornier Do 31
• EWR VJ 101
• Focke-Wulf Fw Triebflügel
• Focke-Wulf Ta 183
• Göppingen Gö 9

• Heinkel He 176
• Heinkel He 178
• Heinkel He 280
• Heinkel He 343
• Henschel Hs 132
• Horten Ho 229 -- Flying wing
• Horten H.IX V1
• Horten H.IX V2
• Horten H.X
• Horten H.XIII
• Horten H.XVIII

• Junkers J 1
• Junkers Ju 287
• Lippisch DM-1
• Lippisch P.13a
• Messerschmitt Me P.1101
• RFB-X-113
• RFB-X-114
• Fiesler Fi 103 R
• VFW VAK 191B (1971)

[edit] Russia

• Beriev VVA-14
• Tupolev ANT-20
• Tupolev Tu-119
• Sukhoi T-4
• Sukhoi Su-47
• Mikoyan Project 1.44

[edit] People's Republic of China

• Chengdu J-9
• Nanchang J-12
• Shenyang J-13

[edit] Others

• Budd BB-1 Pioneer
• EADS Barracuda
  • Hypersonic Technology Vehicle
  • Small Launch Vehicle
  • Hypersonic Cruise Vehicle
• HyShot
• FanWing
• Fouga Gemeaux
• Helios Prototype
• HiMAT
• Pedaliante
• Nord 1500 Griffon
• Schweizer SGS 1-29
• Solar Impulse Project
• PSU Zephyrus

[edit] See also

• List of German WW II prototypes and projects

[edit] References

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