Editing Lockheed XF-90

{{Short description|Experimental aircraft}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
| name = XF-90
| image = File:XF-90 inflight USAFM.jpg
| caption = XF-90 in flight
| type = Fighter
| manufacturer = [[Lockheed Corporation|Lockheed]]
| designer = <!--Only appropriate for single designers, not project leaders-->
| first_flight = 3 June 1949
| introduction = 
| retired = 
| status = Canceled
| primary_user = [[United States Air Force]] (Intended)
| more_users = 
| produced = 
| number_built = 2
| unit cost = US$5.1 million for the program<ref name="knaack">Knaack 1978, p. 325.</ref>
| variants = 
}}

The '''Lockheed XF-90''' was built in response to a [[United States Air Force]] requirement for a long-range [[penetration fighter]] and [[escort fighter|bomber escort]]. The same requirement produced the [[McDonnell]] [[XF-88 Voodoo]]. Lockheed received a contract for two prototype '''XP-90'''s (redesignated '''XF-90''' in 1948). The design was developed by [[Willis Hawkins]] and the [[Skunk Works]] team under [[Clarence Johnson|Kelly Johnson]]. Two prototypes were built ([[United States military aircraft serials|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. Embodying the experience gained in developing the [[P-80 Shooting Star]], the XF-90 shared some design traits with the older Lockheed fighter, albeit with [[swept wing|swept-wings]]; however, this latter design choice could not sufficiently make up for the project’s underpowered engines,<ref name="Jones p. 241">Jones 1975, p. 241.</ref> and the XF-90 never entered production.

==Design and development==
[[File:Lockheed F-90.jpg|right|thumb]]In response to a 1945 Army request for an advanced jet fighter, Lockheed proposed a jet powered initially by a [[Lockheed J37|Lockheed L-1000]] axial flow turbojet, and then the [[General Electric J35]].<ref>Jenkins 2008, p. 138.</ref> Further design refinements included using two [[Westinghouse J34]] engines with afterburners. After data showed that a [[delta wing|delta]] [[planform]] would not be suitable, the Lockheed Model 90 was built in 1947 as a mock-up.<ref>O'Leary 1994, p. 18.</ref>

The final design embodied much of the experience and shared the intake and low-wing layout of the previous [[Lockheed F-80 Shooting Star|P-80 Shooting Star]], but with 35° [[swept wing|swept-back wings]], a sharply-pointed nose, and two [[Westinghouse J34|Westinghouse J34-WE-11]] axial-flow turbojet engines, providing a total thrust of 6,200&nbsp;lbf (27.6&nbsp;kN), mounted side-by-side in the rear fuselage and fed by side-mounted air intakes.<ref name="Jones p. 241"/> The wings had leading edge slats, Fowler flaps, and ailerons on the trailing edge. The pressurized cockpit was fitted with an ejection seat and a bubble canopy. Proposed armament was six 20&nbsp;&nbsp;mm (.79&nbsp;in) cannons. The internal fuel was supplemented by wingtip-mounted tanks, bringing total fuel capacity to 1,665&nbsp;gal (6,308&nbsp;L). The use of 75ST aluminum rather than the then-standard 24ST aluminum alloy, along with heavy forgings and machined parts, resulted in a well-constructed, sturdy airframe. These innovations resulted in an aircraft with an empty weight more than 50% heavier than its competitors.<ref name="Jones p. 241"/>

The first XF-90 used non-afterburning J34s, 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 [[P-80 Shooting Star|F-80]] testbed. Even so, the aircraft remained underpowered.<ref name="Jones p. 241"/>

==Testing and evaluation==
[[File:Lockheed XF-90 parked.jpg|right|thumb|The first XF-90 prototype.]]
[[File:Lockheed XF-90 (46-688) in Yucca Flat.jpg|thumb|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 [[National Advisory Committee on Aeronautics|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.<ref>{{cite web|title=Here's All That Remains After You Drop Nukes on a Fighter Jet|date=November 1, 2021|author=Benny Kirk|website=[[Autoevolution]]|url=https://www.autoevolution.com/news/heres-all-that-remains-after-you-drop-nukes-on-a-fighter-jet-173117.html}}</ref>

==Notable appearances in media==
The XF-90 lived on as the jet fighter aircraft flown by the popular [[Blackhawk (DC Comics)|Blackhawks]] Squadron in the comic book series of the same name, first published by [[Quality Comics]] and later by [[DC Comics]]. The Blackhawks flew fictional "B" and later "C" models all through the 1950s until 1964. Both were improved, single engine production variants of the original twin-engine Lockheed XF-90.<ref>Greenberger 2008, p. 94.</ref>

==Aircraft disposition==
[[File:Lockheed L-090 XF-90A-LO (USAAF sn 46-688, cn 090-1002) (5-18-2023).jpg|thumb|Remains of XF-90A 46-0688 at the [[National Museum of the United States Air Force]].]]
*46-0687 – tested to destruction at [[NACA]] lab in [[Cleveland, Ohio]].<ref>[http://www.joebaugher.com/usaf_serials/1946.html "XF-90/46-687."] ''Joe Baugher serial numbers.'' Retrieved: 10 May 2013.</ref>
*46-0688 – on display 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. Its wings have been removed, and its nose was mangled by the nuclear blasts. During the decontamination process, all rivets were removed to purge radioactive sand. The aircraft is now on display in the museum's Cold War gallery in a diorama depicting it on the Nevada Test Site.<ref>[https://web.archive.org/web/20140203233914/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=8755 "XF-90/46-688"] National Museum of the United States Air Force. Retrieved: 15 July 2017.</ref><ref>[https://www.nationalmuseum.af.mil/Upcoming/Photos/igphoto/2002855699/] National Museum of the United States Air Force. Retrieved: 18 September 2021.</ref>

==Specifications (XF-90A)==
[[File:Lockheed XF-90 3-view line drawing.png|frameless|right|3-view line drawing of the Lockheed XF-90]]

{{Aircraft specs
|prime units?=imp
<!-- if you do not understand how to use this template, please ask at [[Wikipedia talk:WikiProject Aircraft]] -->

|crew=one
|length ft=56
|length in=2
|length m=17.12 
|span ft=40
|span in=0
|span m=12.20 
|height ft=15
|height in=9
|height m=4.80 
|wing area sqft=345 
|wing area sqm=32 
|empty weight lb=18,050 
|empty weight kg=8,204 
|gross weight lb=27,200 
|gross weight kg=12,363 
|max takeoff weight lb=31,060 
|max takeoff weight kg=14,118 
|eng1 name=[[Westinghouse J34]]-WE-15 
|eng1 type=[[turbojet]]s
|eng1 number=2
|eng1 lbf=4,100  
|eng1 kn=18.2 
|max speed mph=665 
|max speed kmh=1,064 
|range miles=2,300 
|range km=3,680 
|ceiling ft=39,000 
|ceiling m=11,890 
|climb rate ftmin=5,555 
|climb rate ms=28.2 
|wing loading lb/sqft=79 
|wing loading kg/m2=386 
|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
}}

==See also==
{{aircontent
|related=
|similar aircraft=<!-- similar or comparable aircraft -->
* [[McDonnell XF-88 Voodoo]]
* [[North American YF-93]]
|lists=
* [[List of Lockheed aircraft]]
* [[List of fighter aircraft]]
* [[List of military aircraft of the United States]]
}}

==References==
===Notes===
{{Reflist}}

===Bibliography===
{{Refbegin}}
* [[Walter J. Boyne|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}}.
* Simone, William J. ''Lockheed XF-90 Penetration Fighter, Air Force Legends 222''. Simi Valley, California, Steve Ginter, 2020. {{ISBN|978-0-9993884-7-1}}.
{{refend}}

==External links==
{{Commons category|Lockheed XF-90}}
* [https://web.archive.org/web/20140203233914/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=8755 USAF Museum: XF-90]
* [http://www.airspacemag.com/video/Operation-Tumbler-Snapper.html Operation Tumbler-Snapper: Atomic Blast Testing]

{{Lockheed}}
{{USAF fighters}}
{{Authority control}}

[[Category:Lockheed aircraft|F-090]]
[[Category:1940s United States fighter aircraft|Lockheed F-90]]
[[Category:Twinjets]]
[[Category:Low-wing aircraft]]
[[Category:Cancelled military aircraft projects of the United States]]
[[Category:Aircraft with retractable tricycle landing gear]]