Lockheed XF-90

XF-90

XF-90 in flight
Role	Fighter
Manufacturer	Lockheed
First flight	3 June 1949
Status	Canceled
Number built	2
Unit cost	US$5.1 million for the program^[1]

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

In response to a 1945 Army request for an advanced jet fighter, Lockheed proposed a jet powered initially by a Lockheed L-1000 axial flow turbojet, and then the General Electric J35.^[2] Further design refinements included using two Westinghouse J34 engines with afterburners. After data showed that a delta planform would not be suitable, the Lockheed Model 90 was built as a mockup in 1947 with swept wings.^[3]

The final design embodied much of the experience and shared the intake and low-wing layout of the previous P-80 Shooting Star, but with 35° sweptback wings, a sharply-pointed nose and two Westinghouse J34-WE-11 axial-flow turbojet engines, providing a total thrust of 6,200 lbf (27.6 kN),mounted side-by-side in the rear fuselage and fed by side-mounted air intakes.^[4] 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 (.79 in) cannons. The internal fuel was supplemented by wingtip-mounted tanks, bringing total fuel capacity to 1,665 gal (6,308 l). 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.^[4]

The first XF-90 used J34s without afterburning, but these lacked the thrust for takeoff as rocket-assisted RATO were required for most of the first flights unless it carried a very low fuel load. The second (XF-90A) had afterburners installed which had been tested on an F-80 testbed. Even so, the aircraft remained underpowered.^[4]

Testing and evaluation

The first XF-90 prototype.

Remains of the second XF-90 prototype.

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 fore and aft for horizontal stabilizer adjustment. Partly because Lockheed's design proved underpowered, it placed second to McDonnell's XF-88 Voodoo which won the production contract in September 1950, before the penetration fighter project was abandoned altogether.

Upon Lockheed 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 Frenchman Flat within the Nevada Test Site in 1952.

Notable appearances in media

The XF-90 lived on as the aircraft flown through the 1950s by the popular Blackhawks Squadron in the comics series of the same name, first published by Quality Comics and later by DC Comics. The Blackhawks flew single-engine "B" and "C" models, fictional production variants of Lockheed's twin-engine XF-90.^[5]

Aircraft disposition

46-0687 - tested to destruction at NACA lab in Cleveland, Ohio.^[6]
46-0688 - in storage and awaiting restoration at the National Museum of the United States Air Force in Dayton, Ohio. In 2003, the heavily damaged hulk was recovered from the Nevada test site and moved there. 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 remove radioactive sand. At present, the museum plans to display the XF-90 in its damaged, mostly unrestored condition, to demonstrate the effects of nuclear weaponry.^[7]

Specifications (XF-90A)

General characteristics

Crew: one
Length: 56 ft 2 in (17.12 m)
Wingspan: 40 ft 0 in (12.20 m)
Height: 15 ft 9 in (4.80 m)
Wing area: 345 ft² (32 m²)
Empty weight: 18,050 lb (8,204 kg)
Loaded weight: 27,200 lb (12,363 kg)
Max. takeoff weight: 31,060 lb (14,118 kg)
Powerplant: 2 × Westinghouse J34-WE-15 turbojets, 4,100 lbf (18.2 kN) each

Performance

Maximum speed: 665 mph (1,064 km/h)
Range: 2,300 mi (3,680 km)
Service ceiling: 39,000 ft (11,890 m)
Rate of climb: 5,555 ft/min (28.2 m/s)
Wing loading: 79 lb/ft² (386 kg/m²)
Thrust/weight: 0.30

Armament

6 × 20 mm (.79 in) cannons
8 × 5 in (127 mm) HVAR rockets
Up to 2,000 lb (907 kg) of bombs

References

Notes

↑ Knaack 1978, p. 325.
↑ Jenkins 2008, p. 138.
↑ O'Leary 1994, p. 18.
1 2 3 Jones 1975, p. 241.
↑ Greenberger 2008, p. 94.
↑ "XF-90/46-687." Joe Baugher serial numbers. Retrieved: 10 May 2013.
↑ "XF-90/46-688" National Museum of the United States Air Force. Retrieved: 14 June 2011.

Bibliography

Boyne, Walter J. Beyond the Horizons: The Lockheed Story. New York: St. Martin's Press, 1998. ISBN 0-312-19237-1.
Greenberger, Robert. "Blackhawk". In Dougall, Alastair. The DC Comics Encyclopedia. London: Dorling Kindersley, 2008. ISBN 0-7566-4119-5.
Jenkins, Dennis R. and Tony R. Landis. Experimental & Prototype U.S. Air Force Jet Fighters. North Branch, Minnesota: Specialty Press, 2008. ISBN 978-1-58007-111-6.
Jones, Lloyd S. U.S. Fighters: Army-Air Force 1925 to 1980s. Fallbrook, California: Aero Publishers Inc., 1975. ISBN 0-8168-9200-8.
Knaack 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.
O'Leary, Michael, ed. "Deep Penetration." America's Forgotten Wings, Volume 1, 1994.
Pace, Steve. Lockheed Skunk Works. St. Paul, Minnesota: Motorbooks International, 1992. ISBN 0-87938-632-0.
Pace, Steve. X-Fighters: USAF Experimental and Prototype Fighters, XP-59 to YF-23. St. Paul, Minnesota: Motorbooks International, 1991. ISBN 0-87938-540-5.

External links

Wikimedia Commons has media related to Lockheed XF-90.

Lockheed and Lockheed Martin aircraft

Airliners and civil transports	Vega Model 8 Sirius Altair Model 9 Orion Model 10 Electra Model 12 Electra Junior Model 14 Super Electra Model 18 Lodestar Constellation L-049 L-649 L-749 L-1049 Super Constellation L-1249 Super Constellation L-1649 Starliner Saturn L-188 Electra L-402 JetStar L-100 Hercules L-1011 TriStar

Military transports	C-69 Constellation C-121 Constellation C-130 Hercules C-130J Super Hercules DC-130 HC-130 KC-130 LC-130 MC-130 C-141 Starlifter C-5 Galaxy R6V Constitution Tristar (RAF)

Attack and bombers	YP-24 Hudson XB-30 Ventura AC-130 A-4AR Fightinghawk F-117 Nighthawk Have Blue FB-22

Drones/UAVs	AQM-60 Kingfisher D-21 Desert Hawk Desert Hawk III MQM-105 Aquila Polecat RQ-3 Darkstar RQ-170 Sentinel

EW and reconnaissance	YO-3 EC-121 Warning Star EC-130 EC-130H Compass Call WC-130 EP-3 U-2 TR-X A-12 SR-71 Blackbird SR-72

Fighters	XFM-2 YP-24 P-38 Lightning XP-49 XP-58 Chain Lightning P-80 Shooting Star XF-90 F-94 Starfire F-104 Starfighter variants YF-12 F-16 Fighting Falcon F-22 Raptor YF-22 F-35 Lightning II

Helicopters	CL-475 XH-51 AH-56 Cheyenne VH-71 Kestrel

Maritime patrol	P-2 Neptune P-3 Orion P-7 S-3 Viking CP-140 Aurora

Trainers	T-33 T2V SeaStar

Experimental	L-133 NF-104A Senior Peg Senior Prom XC-35 XF-104 XV-4 Hummingbird X-7 X-17 X-26B Frigate CL-1200 Lancer X-33 X-35 X-44 X-55 X-56 XFV QueSST

Other	Air Express Big Dipper Model 44 Excalibur Explorer Little Dipper

USAAS/USAAC/USAAF/USAF fighter designations 1924–1962

Pursuit (pre-1948) Fighter (post-1948)	P-1 P-2 P-3 XP-4 P-5 P-6 XP-7 XP-8 XP-9 XP-10 P-11 P-12 XP-13 XP-14 XP-15 P-16 P-17 YP-18 YP-19 YP-20 P-21 XP-22 P-23 YP-24 P-25 P-26 P-27 P-28 P-29 P-30 XP-31 P-32 P-33 XP-34 P-35 P-36 P-37 P-38 P-39 P-40 XP-41 P-42 P-43 P-44 P-45 XP-46 P-47 XP-48 XP-49 XP-50 P-51 XP-52 P-53 XP-54 XP-55 XP-56 XP-57 XP-58 P-59 P-60 P-61/C XP-62 P-63 P-64 P-65 P-66 XP-67 XP-68 P-69 P-70 XP-71 XP-72 P-73 P-74¹ P-75 XP-76 XP-77 P-78 XP-79 P-80 XP-81 F-82 XP-83 F-84 F-85 F-86/D XF-87 F-88 F-89 XF-90 XF-91 XF-92 YF-93 F-94 F-95 F-96 F-97 F-98 F-99 F-100 F-101 F-102 XF-103 F-104 F-105 F-106 F-107 XF-108 XF-109 F-110 F-111/B

Pursuit, Biplace	PB-1 PB-2 PB-3

Fighter, Multiplace	FM-1 FM-2

¹ Not assigned See also: F-24 • F-117 • P-400 • post-1962 sequence

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