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Bell X-1-2

The X-planes are a series of experimental United States aircraft and rockets, used to test and evaluate new technologies and aerodynamic concepts. They have an X designator, which indicates the research mission within the US system of aircraft designations.

Most of the X-planes have been operated by the National Advisory Committee for Aeronautics (NACA) or, later, the National Aeronautics and Space Administration (NASA), often in conjunction with the United States Air Force. The majority of X-plane testing has occurred at Edwards Air Force Base.[1]

Some of the X-planes have been well publicized, while others, such as the X-16, have been developed in secrecy.[2] The first, the Bell X-1, became well known in 1947 after it became the first aircraft to break the sound barrier in level flight.[3] Later X-planes supported important research in a multitude of aerodynamic and technical fields, but only the North American X-15 rocket plane of the early 1960s achieved comparable fame to that of the X-1.[citation needed] X-planes 8, 9, 11, 12, and 17 were actually missiles[4]:14,15,17,18,24 used to test new types of engines, and some other vehicles were un-manned (some were remotely flown, some were partially or fully autonomous).

Most X-planes are not expected to go into full-scale production; one exception was the Lockheed Martin X-35, which competed against the Boeing X-32 during the Joint Strike Fighter Program, and has entered production as the F-35.[5]

Not all US experimental aircraft have been designated as X-planes; some received US Navy designations before 1962,[6] while others have been known only by manufacturers' designations,[N 1] non-'X'-series designations,[N 2] or classified codenames.[N 3]

Contents

ListEdit

List of X-planes
Type Manufacturer Agency Image Date Role Notes
X-1 Bell USAF, NACA   1946 High-speed and high-altitude flight First aircraft to break the sound barrier in level flight.
Proved aerodynamic viability of thin wing sections.[4]:5–7
X-1A
X-1B
X-1C
X-1D
Bell USAF, NACA   1951 High-speed and high-altitude flight
X-1E Bell USAF, NACA   1955 High-speed and high-altitude flight
X-2 Bell USAF   1952 High-speed and high-altitude flight First aircraft to exceed Mach 3.[4]:8
X-3
Stiletto
Douglas USAF, NACA   1952 Highly loaded trapezoidal wing Titanium alloy construction; Underpowered, but provided insights into inertia coupling.[4]:9
X-4
Bantam
Northrop USAF, NACA   1948 Transonic tailless aircraft[4]:10
X-5 Bell USAF, NACA   1951 variable geometry First aircraft to fly with variable wing sweep.[4]:11
X-6 Convair USAF, AEC   1957 Nuclear Propulsion Not built. The Convair NB-36H was a B-36 modified to carry a nuclear reactor and flew from 1955 to 1957.[4]:12[7]
X-7 Lockheed USAF, USA, USN   1951 Ramjet engines.[4]:13
X-8
Aerobee
Aerojet NACA, USAF, USN   1949 Upper air research[4]:14 Later models used as sounding rockets.
X-9
Shrike
Bell USAF   1949 Guidance and propulsion technology Assisted development of GAM-63 Rascal missile.[4]:15
X-10 North American USAF   1953 SM-64 Navajo missile testbed.[4]:16
X-11 Convair USAF   1957 SM-65 Atlas missile testbed.[4]:17
X-12 Convair USAF   1957 SM-65 Atlas missile testbed.[4][4]:18
X-13
Vertijet
Ryan USAF, USN   1955 Vertical takeoff and landing (VTOL) tailsitting VTOL flight.[4]:19
X-14 Bell USAF, NASA   1957 VTOL Vectored thrust configuration for VTOL flight.[4]:20
X-15 North American USAF, NASA   1959 Hypersonic, high-altitude flight First manned hypersonic aircraft; capable of suborbital spaceflight.[4]:21–22
X-15 A-2 North American USAF, NASA   1964 Hypersonic, high-altitude flight Major Pete Knight flew the X-15 A-2 to a Mach 6.70, making it the fastest piloted flight of the X-plane program.
X-16 Bell USAF 1954 High-altitude reconnaissance[4]:23 "X-16" designation used to hide true purpose.[8] Cancelled and never flew.
X-17 Lockheed USAF, USN   1956 High Mach number reentry.[4]:24
X-18 Hiller USAF, USN   1959 Vertical and/or short take-off and landing (V/STOL) Evaluated the tiltwing concept for VTOL flight.[4]:25
X-19 Curtiss-Wright Tri-service   1963 Tandem tiltrotor VTOL[4]:26 XC-143 designation proposed.[9]
X-20
Dyna-Soar
Boeing USAF   1963 Reusable spaceplane Military missions.[4]:27 Cancelled and never built.
X-21A Northrop USAF   1963 Boundary layer control[4]:28
X-22 Bell Tri-service   1966 Quad ducted fan tiltrotor STOVL[4]:29
X-23
PRIME
Martin Marietta USAF   1966 Maneuvering atmospheric reentry[4]:30 Designation never officially assigned.[10]
X-24A Martin Marietta USAF, NASA   1969 Low-speed lifting body[4]:31
X-24B Martin Marietta USAF, NASA   1973 Low-speed lifting body[4]:32
X-25 Bensen USAF   1955 Commercial light autogyro for downed pilots.[4]:33
X-26
Frigate
Schweizer DARPA, US Army, USN  
 
1967 Training glider for yaw-roll coupling
Quiet observation aircraft[4]:34
X-27 Lockheed None   1971 High-performance fighter[4]:35 Cancelled and never flew.
X-28
Sea Skimmer
Osprey USN   1970 Low-cost aerial policing seaplane[4]:36
X-29 Grumman DARPA, USAF, NASA   1984 Forward-swept wing[4]:37
X-30
NASP
Rockwell NASA, DARPA, USAF   1993 Single stage to orbit spaceplane[4]:38 Cancelled and never built.
X-31 Rockwell-MBB DARPA, USAF, BdV   1990 Thrust vectoring supermaneuverability[4]:39
X-32A Boeing USAF, USN, USMC, RAF 2000 Joint Strike Fighter[4]:40–41
X-32B Boeing USAF, USN, RAF   2001 Joint Strike Fighter[4]:40–41
X-33
Venture Star
Lockheed Martin NASA   N/A Half-scale reusable launch vehicle prototype.[4]:42 Prototype never completed.
X-34 Orbital Sciences NASA   N/A Reusable unmanned spaceplane.[4]:43 Never flew.
X-35A Lockheed Martin USAF, USN, USMC, RAF   2000 Joint Strike Fighter[4]:44–45
X-35B Lockheed Martin USAF, USN, USMC, RAF   2001 Joint Strike Fighter[4]:44–45
X-35C Lockheed Martin USAF, USN, USMC, RAF   2000 Joint Strike Fighter[4]:44–45
X-36 McDonnell Douglas NASA   1997 28% scale tailless fighter[4]:46
X-37 Boeing USAF, NASA   2010 Reusable orbital spaceplane[4]:47 Drop test performed in 2006. Five flights since 22 April 2010. (Four launches on Atlas V; one on Falcon 9.)
X-38 Scaled Composites NASA   1998 Lifting body Crew Return Vehicle[4]:48
X-39 Unknown USAF Classified Future Aircraft Technology Enhancements (FATE) program.[4]:49 Designation never officially assigned.[10]
X-40A Boeing USAF, NASA   1998 80% scale Space Maneuver Vehicle
X-37 prototype.[4]:50
X-41 Unknown USAF Classified Maneuvering re-entry vehicle.[4]:51
X-42 Unknown USAF Classified Expendable liquid propellant upper-stage rocket.[4]:52
X-43
Hyper-X
Micro Craft NASA   2001 Hypersonic Scramjet[4]:53
X-44
MANTA
Lockheed Martin USAF, NASA   N/A F-22-based Multi-Axis No-Tail Aircraft thrust vectoring[4]:54 Cancelled, never flew.
X-45 Boeing DARPA, USAF  
 
2002 Unmanned combat air vehicle (UCAV)[4]:55
X-46 Boeing DARPA, USN   N/A Unmanned combat air vehicle (UCAV).[4]:56 Naval use. Cancelled, never flew.
X-47A Pegasus
X-47B
Northrop Grumman DARPA, USN   2003 Unmanned combat air vehicle (UCAV)[4]:57 Naval use.
X-48 Boeing NASA   2007 Blended Wing Body (BWB)[4]:58
X-49
Speedhawk
Piasecki US Army   2007 Compound helicopter
Vectored Thrust Ducted Propeller (VTDP) testbed.[11]
X-50
Dragonfly
Boeing DARPA   2003 Canard Rotor/Wing[4]:60
X-51
Waverider
Boeing USAF   2010[12] Hypersonic scramjet[13]
X-52 Number skipped to avoid confusion with Boeing B-52 Stratofortress.[10]
X-53 Boeing NASA, USAF   2002 Active Aeroelastic Wing[14]
X-54 Gulfstream NASA N/A Low-noise supersonic transport[15] in development.
X-55 Lockheed Martin USAF   2009 Advanced Composite Cargo Aircraft (ACCA)[16]
X-56 Lockheed Martin USAF/NASA   2012 Active flutter suppression and gust load alleviation Part of the high-altitude, long-endurance (HALE) reconnaissance aircraft program.[17]
X-57
Maxwell
ESAero/Tecnam NASA   2016 Low emission plane powered entirely by electric motors[18] Part of NASA's Scalable Convergent Electric Propulsion Technology Operations Research project[18] (SCEPTOR)
X-59 QueSST Lockheed Martin NASA   2018 Prototype quiet supersonic transport aircraft[19]
X-60A Generation Orbit Launch Services USAF 2018 Air-launched rocket for hypersonic flight research [20]

See alsoEdit

NotesEdit

  1. ^ For example, the Piasecki PA-97
  2. ^ For example, the NASA AD-1 and Bell XV-15
  3. ^ For example, the Northrop Tacit Blue

ReferencesEdit

  1. ^ "X-Planes Experimental Aircraft". Federation of American Scientists. Retrieved 2012-06-01.
  2. ^ Miller 2001, p. 209
  3. ^ First Generation X-1 (fact sheet), Dryden: NASA, retrieved May 8, 2010.
  4. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc Jenkins, Landis and Miller 2003
  5. ^ A history of the Joint Strike Fighter Program, UK: Martin-Baker, January 2010, archived from the original on 2010-12-30.
  6. ^ "D-558-I" NASA Dryden Fact Sheets. NASA. Accessed May 8, 2010.
  7. ^ Miller, J. The X-Planes, Speciality Press, 1983.
  8. ^ "X-16". Global security, accessed 11 May 2010.
  9. ^ Baugher 2007
  10. ^ a b c Parsch 2009, "Missing Designations"
  11. ^ Parsch 2009, "DOD 4120.15-L"
  12. ^ "X-51 Waverider makes historic hypersonic flight". US Air Force Public Affairs. 26 May 2010. Retrieved 27 May 2010.
  13. ^ "X-51 Scramjet Engine Demonstrator - WaveRider" globalsecurity.org. Accessed 2010-05-11.
  14. ^ Jordan 2006
  15. ^ 412015-L
  16. ^ Kaufman 2009
  17. ^ Norris 2012
  18. ^ a b Harrington, J.D.; Kamlet, Matt; Barnstorff, Kathy (17 June 2016). "NASA Hybrid Electric Research Plane Gets X Number, New Name". NASA.gov. NASA. Retrieved 17 June 2016.
  19. ^ Jim, Banke (27 June 2018). "NASA's Experimental Supersonic Aircraft Now Known as X-59 QueSST". NASA. Retrieved 28 June 2018.
  20. ^ "U.S. Air Force Designates GO1 Hypersonic Flight Research Vehicle as X-60A". generationorbit.com. 4 October 2018. Retrieved 4 October 2018.

BibliographyEdit

External linksEdit