Aviation: the History of the X Series of Aircraft

This page is an index of the series of the USA X Series Research Aircraft. You may also use our search engine PHOTOVALET(tm) to find other aircraft not found on this page. Our Research Aircraft images can be linked to as follows: Research Aircraft Volume 1, Research Aircraft Volume 2, Research Aircraft Volume 3

Included in the PHOTOVAULT AVIATION Museum are Research Aircraft images of the: Aerocar, Bleroit XI Monoplane, C-8ABuffalo Augmentor, CH-47B, CL-48 Dynavert, CV-990, D-558 Skystreak, Do31, F-107, F4-D2N, Gloster Whittle E28-39, Gossamer Albatross, Gossamer Condor, HiMAT, HK1 Spruce Goose, Hughes H1, Linda Finch, LLRV, M2F3, Me163 Komet, Octave Chanute, Boomerang, Proteus, Voyager, White Knight, Skybaby, Spirit of St. Louis.html, Tacit Blue, TAV-8A Harrier, U-2 TR-1, UH1 VSTOLAND, USAX Series, WASP, Wright Brothers, X-1, X-10, X-13, X-15, X-1B, X-1E, X-2, X-24A, X-24B, X-29, X-3, X-4, X-5., XB-70 Valkyrie, XC-142A, XC-99, XFV1 Pogo, XV-15, XV-5B, X Wing, YB-60, YC-15, YF-16, YO-3A, Visual Reference for Research Aircraft

Aircraft X Number Manufacturer Total Number Built Operating Time Span No. of Flights Primary Testing Facility Achievement Highlights Notes
X- 1 Bell Aircraft 3 1946- 51 157 Edwards AFB First Mach 1+ flight; Maximum altitude of 71,902 ft  
X- 1A Bell Aircraft 1 1953- 55 25 Edwards AFB Obtained speed of Mach 2.44; Maximum altitude of 90,440 ft  
X- 1B Bell Aircraft 1 1954- 58 27 Edwards AFB First reaction controlled flight  
X- 1D Bell Aircraft 1 1951 1 Edwards AFB No major ahcievments, Explosion during captive flight; vehicle jettisoned  
X- 1E Bell Aircraft, Stanley Aircraft (wings) 1 1955- 58 26 Edwards AFB Mach 2.24, altitude 73,458 ft; first flight with ventral fins  
X- 2 Bell Aircraft 2 1952- 56 20 Edwards AFB 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 Led to understanding of inertia coupling
X- 4 Northrop Aircraft 2 1950- 53 82 Edwards AFB Showed tailless craft not suited for transonic flight  
X- 5 Bell Aircraft 2 1952- 55 133 Edwards AFB Successful sweep- wing operation  
X- 6 Convair Division, General Dynamics 1 shield- test aircraft (modified B- 36H) 1955- 57 47 Convair Testing Facility Program terminated before prototypes constructed  
X- 7A,
X- 7A- 3, X- 7B,
X- Q5
Lockheed Missiles 61 1951- 60 130 New Mexico 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 Peak altitude of 121 miles
X- 9 (unmanned) Bell Aircraft 31 1949- 53 28 Holloman AFB 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 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 First ICBM prototypes  
X- 12 (unmanned) Convair Astronautics Division 5 1958 5 Cape Canaveral First intercontinental range mission of 6,325 miles  
X- 13 Ryan Aeronautical Company 2 1955- 57 Unknown Edwards AFB First successful VTOL flight on jet thrust alone  
X- 14,
X- 14A,
X- 14B
Bell Aircraft 1 1957- 81 Unknown Moffet Field 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) 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 Canceled None None None None  
X- 17 (unmanned) Lockheed Missiles 26 1955- 57 26 Holloman AFB High Mach effects on reentry vehicles  
X- 18 Hiller Aircraft 1 1959- 61 20 Edwards AFB First tilt- wing usage for VTOL  
X- 19 Curtiss- Wright 2 1964- 65 50 Caldwell; NAFEC, NJ Dual- tandem tilt propeller use One Equipment failure  
X- 20 Boeing Canceled None None None  
X- 21A Northrop Corporation 2 1963- 64 Unknown Edwards AFB Proved Laminar Flow Control viable  
X- 22A Bell Aerospace 2 1966- 84 501 Bell, Calspan Test Facilities Ducted fan viability, advancement of VTOL technology; One hydraulic system failure  
X- 23A (unmanned) Martin Marietta 4 1966- 67 3 Vandenberg AFB/ Pacific Ocean First maneuverable reentry vehicle  
X- 24A,
X- 24B
Martin Marietta 1 1969- 75 64 Edwards AFB 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 Insight on pilot training  
X- 26A,
X- 26B
Schweizer Aircraft, Lockheed Missiles 6 1967- 88 Unknown Vietnam Use as training vehicle; contributions to stealth designs  
X- 27 Lockheed- California Canceled None None None  
X- 28A George Pereira, Osprey Aircraft 1 1971 Unknown Philadelphia Naval Base, PA Unique contribution as home- built aircraft in X- Plane program  
X- 29A Grumman Aerospace 2 1984- 90 Unknown Edwards AFB First Forsard Swept Wing (FSW) aircraft to fly supersonically in level flight  
X- 30 None selected None None None None  
X- 31A Rockwell International, Deutsche Aerospace 2 1990- 95 523 Edwards AFB 180 degree turn post- stall maneuver Failure of the pitot ­ static system: erroneous total pressure data  
X-33 Lockheed- Martin Skunk Works 1 1999-2000 15 Edwards AFB
X-34 Speeds up to Mach 8 and altitudes of 250,000 feet. The project has a goal of reaching $500K/flight recurring cost and demonstrating a rate of 24 flights in 12 months while maintaining a small work force. The X-34 is a reusable technology testbed vehicle that is designed to demonstrate technologies that are essential to lowering the cost of access to space. The vehicle structure is an all-composite with a one piece delta wing design 58 feet in length and 28 feet wide.
X-37 Designed to be modular to allow for rapid insertion of technologies and experiments The X-37 is 27.5eet long - abouthalf 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.
DC-X McDonnell Douglas 1994-96 White Sands NM Incorporate new advanced technologies for demonstrating the feasibility of single stage to orbit flight The DC-X is designed both to take off and land in a vertical attitude

Key to Acronyms:
AFB = Air Force Base
FDL- 7 = Flight Dynamics Laboratory- 7 (a prototype test craft of the Air Force's Flight Dynamics Laboratory, a predecessor to the X- 24B).
FSW = forward swept wing
ICBM = intercontinental ballistic missile
V/ STOL = vertical/ short takeoff and landing
VTOL = vertical takeoff and landing


NASA's Pathfinder Program is demonstrating advanced space transportation technologies through the use of flight experiments and experimental vehicles. These technology demonstrators and flight experiments will support the Agency's goal of dramatically reducing the cost of access to space and will define the future of space transportation - pushing technology into a new era of space development and exploration at the dawn of the new century.