Lockheed XF-90

infobox Aircraft
name = XF-90
type =Fighter
manufacturer =Lockheed



caption = XF-90 in flight
designer =Willis Hawkins Clarence L. "Kelly" Johnson
first flight =3 June 1949
introduced =
retired =
status = Cancelled
primary user =
more users =
produced =
number built = 2
unit cost = US$5.1 million for the programKnaack Marcelle Size. "Encyclopedia of US Air Force Aircraft and Missile Systems: Volume 1 Post-World War II Fighters 1945-1973". Washington, DC: Office of Air Force History, 1978. ISBN 0-912799-59-5.]
variants with their own articles =

The Lockheed XF-90 was built in response to a United States Air Force requirement for a long-range penetration fighter and bomber escort. The same requirement produced the McDonnell XF-88 Voodoo. Lockheed received a contract for two prototype XP-90s ( redesignated XF-90 in 1948). The design was developed by Willis Hawkins and the Skunk Works team under Kelly Johnson. Two prototypes were built (s/n "46-687" and "-688"). Developmental and political difficulties delayed the first flight until 3 June 1949, with chief test pilot Tony LeVier at the controls. Performance of the design was considered inadequate due to being underpowered, and the XF-90 never entered production.

Design and development

After a redesign from its original delta planform, the Lockheed Model 90 featured 35-degree sweptback wings, a sharply-pointed nose and two Westinghouse J34-WE-11Jones 1975, p. 241.] axial-flow turbojet engines, providing a total of 6200 pounds of static thrust, mounted side-by-side in the rear fuselage and fed by side-mounted air intakes. The wings had leading-edge slats, Fowler flaps and ailerons on the trailing edge. The pressurized cockpit was fitted with an ejector seat and a bubble canopy. Proposed armament was six 20 mm cannons. The internal fuel was supplemented by wingtip-mounted tanks, bringing total fuel capacity to 1,665 US gallons (6308 liters). The use of 75ST aluminum rather than the then-standard 24ST aluminum alloy, along with heavy forgings and machined parts, resulted in an extremely well-constructed and sturdy airframe. However, these innovations also resulted in an aircraft which had an empty weight more than 50 percent heavier than its competitors.

The first XF-90 used J34s without afterburning, while the second (XF-90A) had afterburners installed; these were tested on an F-80 testbed, yet the aircraft remained underpowered.

Testing and evaluation

The XF-90 was the first USAF jet with an afterburner and the first Lockheed jet to fly supersonic, albeit in a dive. It also incorporated an unusual vertical stabilizer that could be moved forward and backward for horizontal stabilizer adjustment. Because Lockheed's design proved underpowered, McDonnell's XF-88 won the production contract in September, 1950.

Upon Lockheed's losing the production contract, the two prototypes were retired to other testing roles. The first aircraft ("46-687") was shipped to the NACA Laboratory in Cleveland, Ohio in 1953 for structural tests. It was no longer flyable, and its extremely strong airframe was tested to destruction. The other ("46-688") survived three atomic blasts at the Frenchman's Flat Nevada Test Site in 1952. The XF-90 lived on in popular culture as the the aircraft of the "Blackhawks" comic book.

In 2003, the heavily damaged hulk of the second XF-90A ("46-688") was recovered from the Nevada test site and moved to the National Museum of the United States Air Force in Dayton, Ohio. It is currently undergoing minor restoration in one of the Museum's restoration facility hangars. Its wings have been removed, and its nose is mangled from the nuclear blasts. During the decontamination process, all the rivets had to be removed to free the plane from radioactive sand. At present, the museum plans to display the plane in its damaged, mostly unrestored condition, to demonstrate the effects of nuclear weaponry.

pecifications (XF-90A)

Aircraft specification

plane or copter?=plane
jet or prop?=jet
crew=One
length main=56 ft 2 in
length alt=17.12 m
span main=40 ft 0 in
span alt=12.20 m
height main=15 ft 9 in
height alt=4.80 m
area main=345 ft²
area alt=32 m²
empty weight main=18,050 lb
empty weight alt=8,204 kg
loaded weight main=27,200 lb
loaded weight alt=12,363 kg
max takeoff weight main=31,060 lb
max takeoff weight alt=14,118 kg
more general=
engine (jet)=Westinghouse J34-WE-15
type of jet=turbojets
number of jets=2
thrust main=4,100 lbf
thrust alt=18.2 kN
max speed main=665 mph
max speed alt=1,064 km/h
range main=2,300 mi
range alt=3,680 km
ceiling main=39,000 ft
ceiling alt=11,890 m
climb rate main=5,555 ft/min
climb rate alt=28.2 m/s
loading main=79 lb/ft²
loading alt=386 kg/m²
thrust/weight=0.30
armament=
* 6x 20 mm cannons
* 8x HVAR rockets
* Up to 2,000 lb (907 kg) of bombs

ee also

aircontent
related=

similar aircraft=

lists=
* List of Lockheed aircraft

References

Notes

Bibliography

* Boyne, Walter J. "Beyond the Horizons: The Lockheed Story". New York: St. Martin's Press, 1998. ISBN 0-31219-237-1.
* Pace, Steve. "Lockheed Skunk Works". Osceola, Wisconsin: Motorbooks International, 1992. ISBN 0-87938-632-0.
* Pace, Steve. "X-Fighters: USAF Experimental and Prototype Fighters, XP-59 to YF-23". Oscela, Wisconsin: Motorbooks International, 1991. ISBN 0-87938-540-5.
* Jones, Lloyd S. "U.S. Fighters: Army-Air Force 1925 to 1980s". Fallbrook, California: Aero Publishers Inc., 1975. ISBN 0-8168-9200-0.

External links

* [http://www.wpafb.af.mil/museum/research/fighter/f90.htm USAF Museum: XF-90]
* [http://findarticles.com/p/articles/mi_qa3897/is_200108/ai_n8957347 Lockheed XF-90]