XF-87 Blackhawk

Development of the XF-87 began at Curtiss-Wright in 1946, it would eventually be intended to be an all-weather interceptor. The Blackhawk was developed from an earlier ground attack, tactical bomber design, the XA-43. The Blackhawk was a response to the initial specification for a jet-powered night fighter, capable of speeds up to 530 mph, issued by the US Army Air Force in August 1945.

A number of companies responded including Bell Aircraft, Consolidated-Vultee, Douglas Aircraft, Northrop, Goodyear and Curtiss-Wright. The US Army Air Force down-selected Northrop’s design – then known as the N-24 and the Curtiss-Wright design- known as the Model 29A.

Curtiss-Wright XF-87 (US Air Force)

The XP-87 had a two-man crew seated side-by-side and was powered by two pairs of Westinghouse XJ34-WE-7 turbojet engines mounted on the wings. In comparison to the sleeker Northrop design, the Blackhawk was a slightly larger, bulkier and heavier aircraft with a straight wing profile. The XJ34-WE-7 turbojets only provided 12,000 lbf and Curtiss-Wright’s test pilot B. Lee Miller described performance in initial tests as sluggish. The Blackhawk’s armament was to consist of four 20mm cannons mounted in a nose turret.

The US Army Air Force designated the Curtiss-Wright jet the XP-87, while Northrop’s N-24 became the XP-89 and full-scale models of both were ordered.

The Curtis XP-87 (Curtiss-Wright, courtesy of Mark Lane)

In June 1948 the newly formed US Air Force re-designated fighters from P to F and the XP-87 became the XF-87 when prototypes were ordered. The XF-87 made its first flight in March 1948. During subsequent flight evaluations in October 1948, the Northrop XF-89 was found to be faster than the XF-87 and the US Navy’s XF3D (Douglas F3D Skyknight). While the Blackhawk was a capable and generally satisfactory aircraft it was deemed to be underpowered. It also reportedly suffered from buffeting at relatively slow speeds.

Walter Tydon’s patent for the Blackhawk’s landing gear (US Patent Office)

Evaluators disliked the Northrop and reportedly favoured the XF-87, however, one evaluating pilot likened its handling to a medium Bomber. An improved faster and more powerful Blackhawk was planned with J47 engines from General Electric. The fate of a second prototype is unclear and sources conflict. Most sources state that the XF-87 never had its armament fitted, however, photographic evidence clearly shows an aircraft, not with a turret, but with four nose mounted guns. This aircraft may be one of the airworthy prototypes or it could be a full-scale mock up built to show the USAAF during the selection process.

Despite the trials favouring the XF-89, the USAF initially ordered 57 F-87A fighters and 30 RF-87A reconnaissance aircraft from Curtiss-Wright in June 1948. Curtis-Wright and the USAF began a publicity campaign to unveil the new fighter, even appearing on the cover of an August edition of Aviation Week and in numerous other aviation publications, but the orders were abruptly cancelled in October 1948 and the USAF moved forward the development of the Northrop XF-89 instead. Check out our video on the F-89 Scorpion linked above.

The ‘F-87’ Blackhawk on the cover of Aviation Week (courtesy of Mark Lane)

The reason for this reversal of the decision is unclear. Only minor faults had been identified during testing and the more powerful J47 engines would have greatly increased the Blackhawk’s speed. The official reason for the cancellation was reportedly a disagreement on the price of a redesigned wing profile. According to his memoir, Walter Tydon, Curtiss-Wright’s chief engineer at the time, believed that some bad blood between Curtiss-Wright’s management and the then-President Harry S. Truman may have led the F-87 contract to be cancelled. Truman was Senator for Missouri from 1935 to 1945 and during that time Tydon believed he had come into conflict with the Curtiss-Wright’s management, perhaps regarding the company’s factory in St. Louis. Without substantial archival research it is difficult to verify either the official reason or Tydon’s theory.

Another potential reason for the cancellation was raised during the Congressional Hearings regarding the B-36 Program, Congressman Charles B. Deane noted that both Curtiss-Wright and Northrop had been informed that “unless they agreed to merge with Consolidated Vultee, business would be bad for them.” The testimony before the hearing notes that Curtiss-Wright were unenthusiastic about a potential merger and this might have been why the F-87 contract was cancelled. The Secretary of the Air Force denied this, however, stating that the cancellation was the result of “operating difficulties with the experimental model of the F-87, plus increasingly satisfactory operating data on competitive all-weather fighters.”

The XF-87 Blackhawk taking off (courtesy of Mark Lane)

Sadly, the prototype XF-87 Blackhawk’s was reportedly scrapped and photographs and footage of the initial flight testing of the Blackhawk is all we have left. The loss of the interceptor contract to Northrop led to the end of Curtiss-Wright’s aircraft production, with the Blackhawk being their last fighter design.

Special thanks to Mark Lane, the grandson of Walter Tydon, Curtiss-Wright’s chief engineer, for taking the time to discuss the Blackhawk and his grandfather’s role in its design.


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Bibliography:

Saga of the P-40 and Curtiss Airplane Division: Its Rise and Demise, W. Tydon

Newest Fighter In the Skies, Aviation Week, 2 Aug. 1948

Ad featured in Army & Navy Journal, Vol. 85, No. 40, 7 Aug. 1948 (source)

Ad featured in Air Force, Vo.31, No.9, Sept. 1948 (source)

‘Investigation of the B-36 Bomber Program’, US Congressional Hearing, Aug.-Oct. 1949, (source)

Curtiss Aircraft, 1907-1947, P.M. Bowers (1987)

American Attack Aircraft Since 1926, E.R. Johnson (2008)

The Big Book of X-Bombers & X-Fighters: USAF Jet-Powered Experimental Aircraft and Their Propulsive Systems, S. Pace (2016)

Curtiss-Wright Aeroplane Factory, Missouri, National Register of Historic Places, US National Park Service (2016) (source)

The Battle of Palmdale – WW2 Drone Hellcat vs F-89 Scorpion Jet Interceptors

The Battle of Palmdale is one of those historic events that could easily spawn clickbait titles: US Navy vs US Air Force, Drone vs Manned Fighter, Runaway WW2 fighter vs Rocket-armed Jet Interceptor. None of these would be a lie! 

Artists impression of the ‘battle’ (Pageant magazine, 1957)

On 16th August, 1956 a US Navy Grumman F6F-5K Hellcat a target drone went rouge over California and the USAF scrambled a pair of Northrop F-89 Scorpions to shoot it down. The F-89s failed to down the Hellcat but did manage to start a serious wildfire. 

Check out the video below:


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Northrop F-89 Scorpion

The Northrop F-89 Scorpion is perhaps one of the lesser known American jet interceptors of the 1950s. To put the F-89 into some context its development began in 1948, intended to be an all-weather interceptor, its stable mates included the F-86 Sabre and the F-84 Thunderjet. The F-89 made its first flight in August 1948 and entered service two years later.

In August 1945 the US Army Air Force released a specification for a new jet-powered night fighter with a speed of up to 530 mph. Jack Northrop began work on a swept wing design which went on to be evaluated with entries from  Bell Aircraft, Consolidated-Vultee, Douglas Aircraft, Goodyear and Curtiss-Wright. The US Army Air Force down-selected Northrop’s design – then known as the N-24 and the Curtiss-Wright XP-87 Blackhawk.

89 Scorpion Testing at Edwards Air Force Base
XF-89 Scorpion Testing at Edwards Air Force Base (USAF/US National Archives)

The Curtiss-Wright XP-87 was a slightly larger, slightly heavier aircraft with its two-man crew seated side-by-side. It was powered by two pairs of Westinghouse XJ34-WE-7 turbojet engines mounted on the wings. In comparison the Northrop design was slimmer, with sept wings and had its two Allison J35 turbojet engines buried low in its fuselage to reduce drag.

The N-24 was designated the XP-89 by the US Army Air Force and a full-scale model was ordered. Aerodynamic testing found that the swept wing was unstable in low speed and a straight, narrow profile was developed and the horizontal stabilizer and cockpit configuration was redesigned.

In 1948 the newly formed US Air Force re-designated fighters from P to F and the XP-89 became the XF-89 when prototypes were ordered. During subsequent flight evaluations the XF-89 was found to be faster than the XF-87 and the US Navy’s XF3D (Douglas F3D Skyknight). Evaluators disliked the Northrop and criticised its cockpit layout, however, the USAF moved forward with its development and scrapped the XF-87.

F-89B at Eglin Air Force Base. Note the external vibration dampeners on the horizontal stabiliser and the 6 cannons in the nose (USAF)

Testing with a second prototype continued and the engines were upgraded with a more powerful Allison J33-A-21 fitted with an afterburner, while concerns about ease of maintenance were answered by having the whole engine capable of lowering out of the fuselage. The XF-89 suffered a number of crashes during testing with a fatal crash on the 22nd February 1950, which killed flight test engineer Arthur Turton when flutter, or vibrations, in the elevator caused the tail of the aircraft to sheer off. The geometry of the rear fuselage and engine exhaust were found to be the cause and were redesigned.

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F-89 firing its 2.75in ‘Mighty Mouse’ Mk 4/Mk 40 Folding-Fin Aerial Rockets (USAF/US National Archives)

Despite the fatal crash the aircraft’s flaws were addressed and production of the XF-89 was greenlit in January 1949, with a contract for 48 F-89s, worth just over $39 million, awarded in May 1949.

The F-89’s armament varied considerably during its service life. Originally it had been intended for the night fighter to have a turret with four forward-firing cannons and another 2 cannon turret firing aft. This was abandoned and the first F-89As had six forward-firing 20mm cannons and the ability to mount rocket pods carrying 16 5in rockets.

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Formation of three rocket-armed F-89Ds of the 59th Fighter Squadron (USAF/US National Archives)

The F-89A was quickly superseded by the B which had the same armaments but improved avionics. The F-89D entered service in October 1954, the D abandoned the cannons and instead had two rocket pods mounting a total of 104 smaller 2.75in ‘Mighty Mouse’ Mk 4/Mk 40 Folding-Fin Aerial Rockets.

Entering service in 1956 the F-89H was equipped with large wingtip pods that could externally carry three GAR-1/2 Falcon missiles each with 21 Mighty Mouse rockets internally. Delays refining the Hughes E-9 fire-control system meant that by the time the H entered service it was outclassed by newer, faster supersonic fighters like the F-100 Super Sabre, F-101 Voodoo and interceptors like the F-102 Delta Dagger and the F-104 Starfighter.

F-89J test firing an AIR-2 Genie tactical nuclear air-to-air rocket. The photograph was captured at the moment of firing during Test Shot John, Operation Plumbbob, 19 July, 1957 (National Nuclear Security Administration)

The F-89J, introduced in 1957, refitted the F-89D with underwing hardpoints for two MB-1 Genie nuclear armed rockets and four Falcon missiles. The J could also carry either the standard F-89D rocket/fuel pod or pure fuel tanks. 350 Js were converted from F-89Ds.

An F-89J has the distinction of being the only aircraft to fire a live MB-1 Genie during Operation Plumbbob (nuclear weapons tests) in July 1957. The MB-1 (later the AIR-2) was an air to air rocket with a 6 mile range and a 1.5 kiloton W25 nuclear warhead. It was ostensibly a tactical nuclear weapon designed to take on Soviet strategic bomber formations.

The USAF began to retire the F-89H in 1959 as more supersonic interceptors entered service and the refitted Js also began to be replaced the same year but remained in Air National Guard service for another decade.

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Flight of F-89s (USAF/US National Archives)

The F-89 is definitely a striking aircraft and a substantial number were built, 1,050 in total but they remain one of the lesser known early Cold War jet fighters. The F-89 featured in our video is an H and is on display at the Hill Aerospace Museum.


If you enjoyed the video and this article please consider supporting our work here. We have some great perks available for Patreon Supporters. You can also support us via one-time donations here.


Bibliography:

Military Aircraft of the Cold War, J. Winchester (2012)

Flying American Combat Aircraft: The Cold War, R. Higham (2005)

Early US Jet Fighters: Proposals, Projects and Prototypes, Tony Buttler (2013)

Archival footage and imagery courtesy of the USAF, the US National Archives and the San Diego Air and Space Museum.