XA XN

XB XO

XC XP

XD XQ

XE XR

XF XS

XG XT

XH XU

XI XV

XJ XW

XK XX

XL XY

XM XZ

X NUMERIC

X YEAR

X-NUMERIC

X.NUMERIC

X/NUMERIC

X Numeric

X1 - Series of light tanks based on WW2 M3A1 [BR]

X - Numeric

X-1 - Experimental aircraft used to Investigate flight beyond the sound barrier, Bell, 1946-51 [US] X-2 - Bell, 1952-56 [USA] X-3 'Stilleto' - Douglas, 1954-56 [US] X-4 'Bantam' - Experimental semi-tailless transonic aircraft, Northrop, 1950-53 [US] X-5 - Series of variable swept-wing geometry aircraft, Bell, 1952-55 [US] X-6 - Expermental nuclear propulsion aircraft, 1955-57, General Dynamics [US] X-7 - Supersonic/hypersonic ramjet testbed, Lockheed, 1951-56 [US] X-8 'Aerobee' - Inexpensive research vehicle/sounding rocket. Aerojet, 1947-56 [US] X-9 'Shrike' - Testbed version of Bell GAM-63 Rascal air-to-surface missile, 1949-53 [US] X-10 - Testbed for SM-64 Navajo cruise missile, North American, 1955-59 [USA] X-11 'Atlas A' - Testbed for XB-65 Atlas ICBM ballistic missile, Convair, 1957-58 [US] X-12 'Atlas B' - One and a half stage test vehicle for Atlas ICBM, Convair, 1958 [US] X-13 - Experimental VTOL jet, Ryan, 1955-58 [US] X-14 - Experimental vectored-thrust VTOL aircraft, Bell, 1957-81 [US] X-15 - Experimental hypersonic flight aircraft, North American, 1959-68 [US] X-16 - Reconnaissance aircraft disguised as an X-plane for secrecy, Bell, 1952 [US] X-17 - Multi-stage rocket used in the investigation of re-entry vehicles, Lockheed, 1955-57 [US] X-18 - Experimental large tilt-wing V/STOL aircraft, Hiller [US] X-19 - Experimental tilt-prop VTOL design, Curtiss-Wright, 1963-65 [US] X-20 'Dyna Soar' - Piloted vehicle for hypersonic/orbital research, Boeing, 1963 [US] X-21 - Modified Douglas WB-660 for boundary layer investigations, Northrop, 1963-64 [US] X-22 - Dual-tandem ducted propeller V/STOL aircraft, Bell Aerospace Textron, 1966-86 [US] X-23 - Tester for hypersonic lifting-body re-entry vehicle, Martin Marietta, 1966-67 [US] X-24 - Tester for hypersonic trans-atmosphere vehicles, Martin Marietta, 1969-75 [US] X-25 - Unpowered/powered gryo-glider used by crew abandoning aircraft, Benson Aircraft, 1969-75 [US] X-26 - Powered sailplanes modified for intelligence purposes, Lockhead/Schweizer, 1967-68 [US] X-27 - Lightweight fighter prototype based on CL-1200 Lancer, Lockheed, 1971 [US] X-28 - Single seat seaplane for police patrols, George Pereira/Osprey Aircraft, 1971 [US] X-29 - Aircraft built to investigate forward swept wing, Grumman Aerospace, 1984-92 [US] X-30 - Single-stage-to-orbit demonstrator for the National AeroSpace Plane, 1994 [US] X-31 X-32 X-33 - VTO/CL space shuttle [US] X-34 - Experiemntal sub-orbital launch vehicle [US] X-35 X-36 X-37 X-38 - Experimental atmospheric test vehicle X-39 X-40 X-41 X-42 X-43 X-44

X.Numeric

Xa

XA - Series of wheeled armoured vehicles, SISU/Patria [FI]

Xb

XB-35

Xc

XC-123 - Transport Aircraft [US] XCG-14 - Transport Aircraft [US] XCG-18 - Transport Aircraft [US] XCG-20 - Transport Aircraft [US]

Xd

Xe

XE-? - Vehicles in the XE-SLED series [US] XE-SLED - Series of marginal-terrain prototypes [US]

Xf

XF-87 - Blackhawk jet prototype, Curtiss [US]

Xg

XG-20 - Transport Aircraft [US]

Xh

Xi

Xj

Xk

Xl

XLDB - cross Linked Double Base

Xm

XM2 - ICV prototype for the Bradley series [US] XM3 - CFV prototype for the Bradley series [US] XM8 - Series of light tanks [US] XM60 - M60 light wrecker prototype [US] XM104 Abrams-based bridgelayer prototype [US] Tracked self-propelled 105mm howitzer [US] XM147 - Superduck prototype [US] XM148 - LARC 5-ton prototype [US] XM190 - Series of 8x8 trucks [US] XM193 - Series of 8x8 trucks [US] XM194 - Series of 8x8 trucks [US] XM214 - .50 calibre 'Minigun', General Electric [US] XM256 - 5.56mm, 5-barreled gatling gun, General Electric [US] XM292 - Truck, 2½-ton, 6x6, box-body, prototype [US] XM381 - 1½-ton 4x4 cargo prototype of the G742 series [US] XM395 - PGMM series prototype [US] XM409 - Series of experimental 10-ton 8x8 trucks, c1956, International Harvester [US] XM410 - Series of 8x8 2½-ton trucks, 1957, Chrysler [US] XM434 - Series of experimental 3½-ton 6x6 trucks, 1957-60, GMC, Ford, Reo [US] XM443 - Truck, ¾ton, 4x4, Cargo and personnel , Willys [US] XM474 - Experimental low-silhouette cargo carrier [US] XM476 - Experimental low-silhouette carrier, Pacific Car and Foundry, 1957 [US] XM520 - Clark-built Goer 16-ton prototype, Clark [US] XM523 - Series of experimental truck/tractor units, Kenworth/International Harvestor [US] XM453 - Series of experimental 5-ton 8x8 trucks, c1960, GMC, Ford, Reo [US] XM571 - Series of full-track articulated utility vehicles, Canadair [CA] XM574 - Semi-trailer, van, electronic, 10-ton, two-axle [US] XM576 - Series of experimental buckshot rounds for 40mm grenade launcher [US] XM583 - Series of white star parachute rounds for 40mm grenade launcher [US] XM585 - Series of white star cluster rounds for 40mm grenade launcher [US] XM651 - Series of Tactical CS rounds for 40mm grenade launcher [US] XM658 - Series of experimental green smoke parachute rounds for 40mm grenade launcher [US] XM659 - Series of experimental red smoke parachute rounds for 40mm grenade launcher [US] XM660 - Series of experimental yellow smoke parachute rounds for 40mm grenade launcher [US] XM661 - Series of experimental green star parachute rounds for 40mm grenade launcher [US] XM662 - Series of experimental red star parachute rounds for 40mm grenade launcher [US] XM663 - Series of experimental green star cluster rounds for 40mm grenade launcher [US] XM664 - Series of experimental red star cluster rounds for 40mm grenade launcher [US] XM667 - Prototype base vehicle for the Lance SSM system [US] XM669 - Series of experimental violet smoke parachute rounds for 40mm grenade launcher [US] XM674 - Series of experimental riot control CS rounds for 40mm grenade launcher [US] XM675 - Series of experimental riot control CS rounds for 40mm grenade launcher [US] XM676 Series of experimental yellow smoke canopy rounds for 40mm grenade launcher [US] Military version of the FC170 with cargo body, 1962, Kaiser Jeep [US] XM677 - Miltary version of the FC170 with crew cab body, 1962, Kaiser Jeep [US] XM678 - Miltary version of the FC170 with bus body, 1962, Kaiser Jeep [US] XM679 Miltary version of the FC170 with ambulance body, 1962, Kaiser Jeep [US] Series of experimental green smoke canopy rounds for 40mm grenade launcher [US] XM680 - Series of experimental white smoke canopy rounds for 40mm grenade launcher [US] XM681 - Series of experimental violet smoke canopy rounds for 40mm grenade launcher [US] XM682 - Series of experimental red smoke canopy rounds for 40mm grenade launcher [US] XM687 - Prototype Lance TEL with fixed launcher [US] XM688 - Prototype Lance transloader [US] XM695 - Series of experimental orange star parachute rounds for 40mm grenade launcher [US] XM696 - Series of experimental yellow smoke streamer rounds for 40mm grenade launcher [US] XM697 - Series of experimental green smoke streamer rounds for 40mm grenade launcher [US] XM698 - Series of experimental orange smoke streamer rounds for 40mm grenade launcher [US] XM699 - Series of experimental red smoke streamer rounds for 40mm grenade launcher [US] XM700 - Series of experimental brown smoke streamer rounds for 40mm grenade launcher [US]. XM701 - Series of experimental violet smoke streamer rounds for 40mm grenade launcher [US] XM715 - Series of 1¼-ton 4x4 utility vehicles, Kaiser-Jeep [US] XM729 - Series of command & reconnaissance prototypes based on M116 [US] XM733 - Series of armoured cargo & peronnel prototypes based on the M116 [US] XM734 - IFV Prototype [US] XM752 - Prototype |Lance TEL with removable launcher [US] XM759 - Series of marginal terrain vehicles, Pacific Car and Foundry [US] XM765 - IFV Prototype [US] XM778 - Truck, 2½-ton, 6x6, cargo, dropside, prototype [US] XM800 - Designation applied to vehicles in the ARSV Program [US] XM806 - Winch-equipped recovery versions of the M113 [US] XM984 - ERMC series prototype [US] XM991 - Semi-trailer, van, 10-ton, two-axle [US] XM992 - Series of experimental Infra-red illumination rounds for 40mm grenade launcher [US] XM995 - Semi-trailer, van, 10-ton, two-axle [US] XM1001 - Prototype for the M1001 10-ton 8x8 tractor [US] XM1002 - Prototype for the M1002 10-ton 8x8 wrecker [US] XM1006 - Prototype for the M1006 series of semi-trailers [US] XM1101 - Large Area Mobile Protected Smoke System [US] XM1102 - 10-ton Heavy Expanded Mobility Tactical Truck (HMETT) Palletized Load System (PLS) Tractor Truck [US] XM1108 - Mobile Tactical Vehicle Light (MTVL) Universal Carrier [US] XM1117 - Series of 4-wheel armoured cars [US] XMGM - eXperimental MGM

Xn

Xo

Xp

XP-67 - Series of experimental multi-engine aircraft, McDonnell [US]

Xq

Xr

Xs

Xt

Xu

Xv

XV-3 - Series of tilt-rotor VTOL aircraft, Bell, 1950 [USA] XV-5 - Series of experimental VTOL aircraft, General Electric [USA] XV-15 - Series of experimental VTOL aircraft, Bell [USA]

Xw

Xx

Xy

Xz