- XV-4 Hummingbird
infobox Aircraft
name = XV-4 Hummingbird
type = VTOL
manufacturer = Lockheed
caption = First prototype XV-4 Hummingbird
designer =
first flight =7 July 1962
introduced =
retired =
produced =
number built = 2
status = Retired
unit cost =
primary user =United States Army
more users =
developed from =
variants with their own articles =The Lockheed XV-4 Hummingbird (originally designated VZ-10) was a U.S. Army project in the 1960s, one of many attempts to produce aV/STOL vertical take off / landing jet. At a design speed of 336 mph, the Hummingbird was slower than some propeller-powered transports.The design used doors at the top and bottom of the fuselage intended to augment thrust ejected into this area with cold air. In theory, a 11,607 lb aircraft could be lifted by a 6,600 lbf engine. Unfortunately, performance was far below the estimates only 1.04 thrust-to-weight in practice and the prototype crashed on
10 June 1964 , killing the pilot. The second aircraft was converted tolift jet s instead, also crashing after several tests.Rockwell's
XFV-12 would be even less successful at venting cold air to augment thrust through the wings. The LockheedF-35 Joint Strike Fighter would later employ a shaft-driven lift fan, also located in the fuselage and drawing on the lessons of the Hummingbird.None of the early American V/STOL designs would result in a production plane. The British
Hawker Siddeley Harrier used vectoring nozzles, while the RussianYakovlev Yak-38 Forger attack jet used lift jets in conjunction with rotating rear nozzles.pecifications (first prototype)
aircraft specifications
plane or copter?=plane
jet or prop?=jetcrew=
capacity=
length main= 32 ft
length alt= 10.3 m
span main= 26 ft
span alt= 7.9 m
height main= 11 ft 8 in
height alt= 3.58 m
area main=
area alt=
airfoil=
empty weight main=
empty weight alt=
loaded weight main= 11,607 lb
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=engine (jet)=
Pratt & Whitney JT12 A
type of jet=turbojets
number of jets=2
thrust main= 3,300 lbf
thrust alt=
thrust original=
afterburning thrust main=
afterburning thrust alt=
engine (prop)=
type of prop=
number of props=
power main=
power alt=
power original=max speed main=336 mph
max speed alt= 541km/h
cruise speed main=
cruise speed alt=
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main=
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ceiling main=
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ee also
aircontent
related=
similar aircraft=
*XV-5 Vertifan
* XFV-12
*Hawker P.1127 lists=
*List of military aircraft of the United States
*List of Lockheed aircraft
*List of VTOL aircraft see also=
References
* X-Planes and Prototypes by Jim Winchester
* [http://avia.russian.ee/air/usa/lok_hummingbird.html Lockheed VZ-10 Hummingbird/XV-4]
* [http://www.vstol.org/wheel/VSTOLWheel/LockheedXV-4A.htm VSTOL.org Wheel]
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