List of experimental aircraft

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.

U.S. "X" designations

Purely-experimental designs

*X-1
*X-2 Starbuster
*X-3 Stiletto
*X-4 Bantam
*X-5
*X-6
*X-7
*X-8
*X-9 Shrike
*X-10
*X-11
*X-12
*X-13 Vertijet
*X-14
*X-15
*X-16
*X-17
*X-18
*X-19
*X-20 Dyna-Soar
*X-21
*X-22
*X-23
*X-24
*X-25
*X-26 Frigate
*X-27 Lancer
*X-28 Sea Skimmer
*X-29
*X-30
*X-31 Enhanced Fighter Maneuverability program
*X-32
*X-33 VentureStar
*X-34
*X-35
*X-36
*X-37
*X-38
*X-39
*X-40
*X-41 Common Aero Vehicle
*X-42 Pop-Up Upper Stage
*X-43 Hyper-X
*X-44 MANTA
*X-45
*X-46
*X-47 Pegasus
*X-48
*X-49
*X-50 Dragonfly
*X-51
*X-53 Active Aeroelastic Wing (AAW) flight demonstrator

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
*Convair XA-41

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

XC Series

*LTV XC-142
*Convair XC-99

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

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
*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 Swift1
*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

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.

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

U.S. non-"X" designations

*Boeing
**Boeing Bird of Prey
**Boeing Skyfox
*Douglas D-588-I Skystreak
*Douglas D-588-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

United Kingdom

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

*Armstrong Whitworth A.W.52
*Avro
**Avro 707
*Blackburn B-20
*Boulton Paul
**Boulton Paul P.111
**Boulton Paul P.120
*Bristol Aircraft Ltd
**Bristol 188
**Bristol Brabazon
*British Aerospace EAP
*de Havilland Swallow
*English Electric P1A
*Fairey
**Fairey Delta 1
**Fairey Delta 2
**Fairey Rotodyne
*General Aircraft GAL.56
*Gloster E.28/39
*Handley Page
**Handley Page Manx
**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
*Hunting
**Hunting H.126
*Miles Libellula
*Rotabuggy
*Saunders Roe
**Saunders-Roe SR.A/1
**Saunders-Roe SR.53
**Saunders-Roe SR.177
*Short Brothers
**Short Shetland
**Short Sperrin
**Short SB.1
**Short SB5
**Short Sherpa
**Short SC.1
*TSR-2
*Westland-Hill Pterodactyl

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 Ho IX V1
* Horten Ho IX V2
* Horten Ho X
* Horten Ho XIII
* Horten Ho 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)

Russia

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

Others

*Avro Canada
**Avrocar
*EADS Barracuda
**Hypersonic Technology Vehicle
**Small Launch Vehicle
**Hypersonic Cruise Vehicle
*FanWing
*Fouga Gemeaux
*Helios Prototype
*HiMAT
*Nord 1500 Griffon
*Schweizer SGS 1-29
*Solar Impulse Project

ee also

*List of German WW II prototypes and projects