# LOCKHEED XF-90



## johnbr (Aug 2, 2020)

LOCKHEED XF-90 LARGE VINTAGE PHOTO US AIR FORCE USAF | eBay

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## johnbr (Aug 2, 2020)



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## johnbr (Aug 3, 2020)



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## johnbr (Aug 3, 2020)

all from













net

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## MIflyer (Aug 3, 2020)

The F-90B model used a single larger engine and had some success as the mount of a special ops unit.

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## vikingBerserker (Aug 3, 2020)

Nice!


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## pgeno71 (Aug 3, 2020)

Very cool, thanks for sharing.


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## johnbr (Aug 3, 2020)

*Status:
Fighter - XF-90:*
Wing area = 350 sq. ft.
Span = 40.0 ft.
Length = 56.2 ft.
Height = 15.8 ft. 

1. Teletype Authorization: 11 April 1946
2. Contract Date: 20 June 1946
3. Mock-up Inspection: December 1947
4. Engineering Inspection: April 1949
5. First Flight: (1st Art.) 3 June 1946; (2nd Art.) March 1950 
*Power Plant:*
(2) XJ34-WE-11 Westinghouse 
ENGINE RATINGS
S.L. Static LB - RPM
Max: *4100 - 12500
Mil: 2920 - 12500
Nor: 2420 - 11800 
*with afterburners operating ATO

No & Model
(4) 12AS1000D4
Mfr Aerojet
Thrust Lb (ea) 1000
Duration (sec) 12
*Features:*
Crew: 1
Pressurization
Cooling & Heating
AN/APG-5 Radar
A-1B Gun-Bomb-Rocket Sight
Ejection Seat
Dive Brakes
Automatic Slats
Adjustable Stabilizer
Aileron Boost
Two-Position Fowler Flaps
Max fuel capacity: 1665 gal. 
*Armament:*
Turrets: None
Guns: 6 x 20mm
Ammunition (tot): 1602 rds.
Max Bomb Load: 2 x 1000 lb.
Max Bomb Size 1000 lb.
Rockets: 8 x 5" HVAR


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## johnbr (Aug 3, 2020)



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## johnbr (Aug 3, 2020)

1946 USAAF Penetration Fighter (XF-88, XF-90)

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## johnbr (Aug 3, 2020)



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## johnbr (Aug 3, 2020)

Flickr
Tony LeVier at the controls, Lockheed XF-90

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## johnbr (Aug 3, 2020)



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## Gnomey (Aug 3, 2020)

Good shots!


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## johnbr (Aug 3, 2020)

Design and development 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 mock-up 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 Lockheed F-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 evaluatio 
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[edit source | editbeta]

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 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

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## johnbr (Aug 3, 2020)

The mock-up

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## rprosperi (Aug 6, 2020)

An awesome new book from Ginter Books has an amazing amount of detail about the XF-90, well more than any other publication I've ever found, including lots of info about how one of the prototypes was used as a target during some atomic testing at the NTS, then later rescued by the NMUSAF and will eventually be displayed there.

Book details here:

Lockheed XF-90, Penetration Fighter by By William Simone.

Also available at Amazon, etc.

Very satisfying for anyone that ever loved this plane and wanted to know more (and that's like most of us here, right?)


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## Juanita (Aug 10, 2020)

Thanks for posting all these photos John.
I was given the opportunity to illustrate this aircraft recently.
It was not a type I had taken notice of previously...so I learnt a lot doing this artwork.

Juanita

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## davparlr (Aug 11, 2020)

Love the pictures. I have already expressed my admiration for the XF-90. It is too bad they overbuilt the aircraft. Both Lockheed and the AF missed a great opportunity to have powerful multipurpose fighter available in mid to late 50s, several years before the F-4. It is interesting to compare the XF-90 shown in 3rd Pix from top, above, and the F3H-G/H, shown below from wikipedia, soon to be identified as the F4H Phantom II. It does seem that Lockheed had done a better aerodynamic design work on the XF-90. The wings of the XF-90 appear to have a slight dihedral whereas the F3H-G , pictured below, appears to possibly have a slight anhedral, certainly no dihedral, this led to the stability correction of the dihedral wing tips on the F4. Also, the XF-90’s horizontal stabilizer is mounted higher up the vertical stabilizer which would mitigate, though not eliminate, blanking of the horizontal stabilizer during high angle of attack maneuvers. The large anhedral horizontal stabilizer was another F4H aerodynamic modification to fix the blanking problem. A better solution for the XF-90 would have been to locate the horizontal stabilizer below the engines ala F-100. This was not available for the F3H-G.

Also, interestingly, in the drawing of the XF-90s nose section it shows the machine gun placement in the nose. Later picture show gun location below the engine inlets. Changed to prevent gunfire gas ingestion into the inlets?

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## MIflyer (Aug 15, 2020)



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## rprosperi (Aug 15, 2020)

Thanks for posting that!

"The XF-90 exceeded the speed of sound in level flight...."

So, fake news goes as far back as October 1949 at least...

About the only thing everyone agreed on about the XF-90 is that it was under-powered and never performed well enough, typically blamed on under-performing engines or excessive airframe weight, depending on who was blaming whom.

Still, a really beautiful plane, that I'll always enjoy reading more about.

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## Gnomey (Aug 21, 2020)

Nice shots!


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## davparlr (Aug 21, 2020)

rprosperi said:


> "The XF-90 exceeded the speed of sound in level flight...."
> 
> So, fake news goes as far back as October 1949 at least...


You're assuming that there was a time when there was no fake news?



> About the only thing everyone agreed on about the XF-90 is that it was under-powered and never performed well enough, typically blamed on under-performing engines or excessive airframe weight, depending on who was blaming whom.



I think both. If the plane had started in the early 50s with better understanding of material and needed structural strength requirements and knowledge of area rule and the upcoming J-79 engine, I think the AF could have been fielding a multipurpose fighter by 1957, which could have been lighter, faster (smaller wings although temperature limit of alumium could be limiting) aircraft prior to the F-4, and could replace the F-100, F-102, F-104, and F-106. And they would not have had a need to buy the heavier Navy F-4.


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