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X-Planes Experimental Aircraft

Summary of the X- Plane Program

Model Manufacturer No. of Vehicles Built Years of Operation No. of Flights Primary Testing Facility Research Goals Program Achievements
X- 1 Bell Aircraft 3 1946- 51 157 Edwards AFB Investigate flight characteristics at greater than sonic velocities. Structural, physiological phenomena within transonic speed envelope First Mach 1+ flight; Maximum altitude of 71,902 ft
X- 1A Bell Aircraft 1 1953- 55 25 Edwards AFB Continue X- 1 goals at higher speeds and altitudes Obtained speed of Mach 2.44; Maximum altitude of 90,440 ft
X- 1B Bell Aircraft 1 1954- 58 27 Edwards AFB Exploratory aerodynamic heating tests; experimental reaction control system First reaction controlled flight
X- 1D Bell Aircraft 1 1951 1 Edwards AFB Continue X- 1 goals at higher speeds and altitudes No major milestones, Explosion during captive flight; vehicle jettisoned
X- 1E Bell Aircraft, Stanley Aircraft (wings) 1 1955- 58 26 Edwards AFB High- speed wing performance Mach 2.24, altitude 73,458 ft; first flight with ventral fins
X- 2 Bell Aircraft 2 1952- 56 20 Edwards AFB Swept- wing performance; higher speeds and altitude than X- 1 New altitude record of 126,200 ft; new speed record of Mach 2.87
Gasket explosion destroyed first X- 2; second aircraft lost to inertial coupling
X- 3 Douglas Aircraft 1 1954- 56 20 Edwards AFB High speed aerodynamic phenomenon; titanium construction; take off, land under its own power Led to understanding of inertia coupling
X-4 Northrop Aircraft 2 1950- 53 82 Edwards AFB Test tailless, semi- tailless configuration at transonic speeds Showed tailless craft not suited for transonic flight
X- 5 Bell Aircraft 2 1952- 55 133 Edwards AFB Investigate aerodynamics of variable- seep- wing design Successful sweep- wing operation
X- 6 Convair Division, General Dynamics 1 shield- test aircraft (modified B- 36H) 1955- 57 47 Convair Testing Facility Test feasibility of nuclear propulsion Program terminated before prototypes constructed
Lockheed Missiles 61 1951- 60 130 New Mexico Test viability of ramjet engines for anti- aircraft missiles; modified to testing of powerplants Obtained Mach 4.31, first air- breathing full- scale research aircraft designed as Mach 3 testbed
X- 8A,
X- 8B,
X- 8C,
X- 8D
Aerojet Engineering 108 (X- 8 designation)
800+ Aerobees
1947- 56 Unknown White Sands, Holloman AFB Upper air research, parachute recovery system Peak altitude of 121 miles
X- 9 (unmanned) Bell Aircraft 31 1949- 53 28 Holloman AFB Test air- to- surface missiles; guidance systems, etc. First chemical warhead test vehicle to test supersonic clusterable dispersion
9 unsuccessful flights
X- 10 (unmanned) North American Aviation 13 1955- 59 15 Edwards AFB Testbed for Navaho intercontinental cruise missile components Established technology base for remote control; first Mach 2- capable target drone
3 unsuccessful flights Communications disruption; miswiring; autopilot malfunction
X- 11 (unmanned) Convair Astronautics Division 8 1956- 58 8 Cape Canaveral Provide flight data for Atlas missile Atlas A First ICBM prototypes
X- 12 (unmanned) Convair Astronautics Division 5 1958 5 Cape Canaveral Test propulsion- staging guidance system, nose reentry configuration Atlas B First intercontinental range mission of 6,325 miles
X- 13 Ryan Aeronautical Company 2 1955- 57 Unknown Edwards AFB Test pure- jet vertical takeoff and landing First successful VTOL flight on jet thrust alone
X- 14,
X- 14A,
X- 14B
Bell Aircraft 1 1957- 81 Unknown Moffet Field Test VTOL technology First VTOL aircraft using jet thrust diverter system for vertical lift
X- 15,
X- 15A- 2
North American Aviation 3 1959- 68 199 X- 15 High Range (Wendover, UT, to Edwards AFB) Explore problems of space and atmospheric flight at very high speeds and altitudes First manned hyper- sonic flight vehicle; altitude of 354,200 ft obtained; Mach 6.7 reached 4 Mid- flight explosions (2); loss of control (1); collapsed landing gear (1)
X-16 Bell Aircraft None None None None High- altitude, long- range reconnaissance aircraft Canceled
X-17 (unmanned) Lockheed Missiles 26 1955- 57 26 Holloman AFB Explore reentry characteristics High Mach effects on reentry vehicles
X- 18 Hiller Aircraft 1 1959- 61 20 Edwards AFB Explore large VTOL vehicles First tilt- wing usage for VTOL
X- 19 Curtiss- Wright 2 1964- 65 50 Caldwell; NAFEC, NJ Test VTOL technology using radial lift Dual- tandem tilt propeller use One Equipment failure
X- 20 Boeing Canceled None None None Piloted orbital flight Provided heat materials testing
X- 21A Northrop Corporation 2 1963- 64 Unknown Edwards AFB Test full- scale boundary control on large aircraft Proved Laminar Flow Control viable
X- 22A Bell Aerospace 2 1966- 84 501 Bell, Calspan Test Facilities Research dual- tandem- ducted propeller configuration; research V/ STOL handling using variable stability system design Ducted fan viability, advancement of VTOL technology; One hydraulic system failure
X- 23A (unmanned) Martin Marietta 4 1966- 67 3 Vandenberg AFB/ Pacific Ocean Test configurations, control systems, and ablative materials for hypersonic reentry vehicles First maneuverable reentry vehicle
X- 24A,
X- 24B
Martin Marietta 1 1969- 75 64 Edwards AFB Research of aerodynamics, flight characteristics of manned vehicle with FDL- 7 configuration [FDL- 7 = Flight Dynamics Laboratory- 7, a prototype test craft of the Air Force's Flight Dynamics Laboratory, a predecessor to the X- 24B].
Verified theoretical advantages of lifting body configuration for hypersonic trans- atmospheric aircraft
X- 25,
X- 25A,
X- 25B
Bensen Aircraft 3 1968 None Raleigh, NC Test gyrocopter discretionary descent vehicle designs Insight on pilot training
X- 26A,
X- 26B
Schweizer Aircraft, Lockheed Missiles 6 1967- 88 Unknown Vietnam Develop ultra-quiet surveillance aircraft Use as training vehicle; contributions to stealth designs
X- 27 Lockheed- California Canceled None None None Advanced, lightweight fighter CL-1200 Lancer
Osprey 1
George Pereira, Osprey Aircraft 1 1971 Unknown Philadelphia Naval Base, PA Explore usefulness of small, single- place seaplane for civil police patrol in Southeast Asia Unique contribution as home- built aircraft in X- Plane program
X- 29A Grumman Aerospace 2 1984- 90 Unknown Edwards AFB Enhanced Fighter Maneuverability (EFM) demonstrator with technologies to provide maneuver agility during close-in aerial combat. Test forward- swept wing design, advanced composites, other aerodynamic advances First forward swept wing [FSW] aircraft to fly supersonically in level flight
X- 30 None selected None None None None Experimental aerospace plane able to operate at hypersonic velocities or accelerating directly into orbit. Serve as testbed for sustained hypersonic speeds within atmosphere or as space vehicles for orbital payload delivery. None. Cancelled.
X- 31A Rockwell International, Deutsche Aerospace 2 1990- 95 523 Edwards AFB Break "stall- barrier," examine angles of attack 180 degree turn post- stall maneuver Failure of the pitot - static system: erroneous total pressure data
Boeing 28 Sept 2000 X-32A first contractor team full-scale technology demonstrator aircraft intended to validate technologies relevant to fielding a multi-service aircraft
X-32B full-scale technology demonstrator aircraft intended to validate technologies relevant to fielding a multi-service aircraft
X-32C Joint Advanced Strike Technology (JAST) program full-scale technology demonstrator aircraft intended to validate technologies relevant to fielding a multi-service aircraft with catapult and arresting capability
X-33 Lockheed- Martin Skunk Works 1 1999-2000 15 Edwards AFB Develop reusable single- stage- to- orbit transportation vehicle
X-34 Orbital Sciences Reusable technology testbed vehicle to demonstrate technologies for lowering the cost of access to space. Goals included speeds up to Mach 8 and altitudes of 250,000 feet, with $500K/flight recurring cost at a rate of 24 flights in 12 months while maintaining a small work force. The vehicle structure is an all-composite with a one piece delta wing design 58 feet in length and 28 feet wide.
Lockheed Martin 24 Oct 2000 X-35A first contractor team full-scale technology demonstrator aircraft intended to validate technologies relevant to fielding a multi-service aircraft
X-35B full-scale technology demonstrator aircraft intended to validate technologies relevant to fielding a multi-service aircraft
X-35C Joint Advanced Strike Technology (JAST) program full-scale technology demonstrator aircraft intended to validate technologies relevant to fielding a multi-service aircraft with catapult and arresting capability
X-36 Boeing 17 May 1997 Remotely piloted research vehicle used to demonstrate the feasibility for a tailless agile fighter.
Future - X
Boeing Experimental flight vehicle which will integrate and test earth-to-orbit and orbit-to-orbit reusable space transportation technologies. Designed to be modular to allow for rapid insertion of technologies and experiments. The X-37 is 27.5eet long - about half the length of the Shuttle payload bay and weighs about 6 tons. Its wingspan is about 15 feet, nd it contains an experiment bay 7 eet long and 4 feet in diameter.
Scaled Composites Fall 1997 Experimental demonstrator for Crew Return Vehicle, droppped from a B-52. Concept model for a crew return vehicle, a "lifeboat" for returning space crew members to earth
X-39 reserved for USAF Research Lab, Future Aircraft Technology Enhancements (FATE) Program
Boeing August 1998 USAF Space Maneuver Vehicle, dropped to validate autonomous landing
X-41 maneuverable re-entry vehicle Classified program
X-42 experimental rocket/motor Classified program
MicroCraft scramjet demonstrator vehicle
Lockheed Martin/Boeing MANTA - Multi-Axis No-Tail Aircraft
Boeing 2nd qtr 2001 Edwards Unmanned Combat Air Vehicle
X-46 Boeing F/A-18 "manned surrogat" to test a low-cost approach to the US Navy's naval unmanned combat air vehicle (UCAV-N) demonstration
Pegasus UCAV
Northrop Grumman Naval Unmanned Combat Air Vehicle (UCAV-N) Advanced Technology Program (ATP)
X-48 Boeing 3 2007-2013 Blended Wing Body (BWB)
X-49 Speedhawk Piasecki Aircraft 1 2007 compound helicopter
Boeing 2 Dec 2003
US Army Proving Ground, Yuma, AZ Canard Rotor/Wing (CRW)
X-51 Boeing + P&W Dec 2008
01 May 2013
Scramjet Engine Demonstrator - WaveRider (SED-WR)
X-52 0 Number skipped to avoid confusion with B-52
X-53 Boeing Phantom Works 1 November 2002 - completed in the spring of 2005 NASA, USAF Active Aeroelastic Wing testbed.
X-54 Gulfstream Aerospace 0 TBD NASA Future Supersonic transport testbed.
Lockheed Martin Skunk Works 1 June 2, 2009 USAF Advanced Composite Cargo Aircraft (ACCA). Molded composite fuselage and empennage testbed.
Multi-Use Technology Testbed [MUTT]
Lockheed Martin Skunk Works 2 2013 USAF/NASA Active flutter suppression and gust load alleviation technology for potential use in future high-altitude, long-endurance (HALE) reconnaissance aircraft.
X-57 Maxwell
Sceptor LEAPTech
TBD ? ? before 2026 ? electice motors with blown wing
Blended Wing Body
TBD ? ? before 2026 ? X-plane designator un-assigned as of 2016, one of several potential aircraft under New Aviation Horizons X-planes plan of 2016
Ultra-efficient Subsonic Aircraft
TBD ? ? before 2026 ? double bubble passenger plane
Quiet Supersonic Technology (QueSST)
TBD ? ? before 2026 ?
VTOL X-Plane
X-61 un-assigned as of 2016
X-100 Curtiss-Wright 1 1958-59 Caldwell, NJ demonstrate radial lift study the effects of downwash
Key to Acronyms:
AFB = Air Force Base
ICBM = intercontinental ballistic missile
V/STOL = vertical/ short takeoff and landing
VTOL = vertical takeoff and landing

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