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Grumman XP-50 (Skyrocket)

United States (1941)

Detailing the development and operational history of the Grumman XP-50 (Skyrocket) Twin-Engine Fighter Prototype.

 Entry last updated on 2/13/2018; Authored by Staff Writer; Content ©

  Grumman XP-50 (Skyrocket)  
Picture of Grumman XP-50 (Skyrocket) Twin-Engine Fighter Prototype
Picture of Grumman XP-50 (Skyrocket) Twin-Engine Fighter Prototype

The Grumman XP-50 came in a close second to the Lockheed XP-38 for the U.S. Army - the latter going on to earn legendary status for its actions in World War 2.

Firmly entrenched as an aircraft supplier to the United States Navy, the Grumman aircraft company set about to supply an equally lucrative deal with the U.S. Army to produce a hybrid high-speed pursuit fighter and light bomber platform. Having developed the radical-looking XF5F-1 Skyrocket in the late-1930's, Grumman chose to forward this concept with a few design alterations to suit Army requirements. These included the addition of a longer nose section to accommodate a nose landing gear and make for a tricycle landing system not to dissimilar to that as showcased by the Bell corporation and its "Airacobra" series. The resulting design sparked enough interest from the United States Army to contract for a flyable prototype with the designation of "XP-50".

The XP-50 showcased many similarities to its predecessor. The pilot sat in a stubby yet streamlined fuselage with the lengthened nose extending just beyond the engine nacelles. The engines were held in low-mounted monoplane wings, all forward of the cockpit. The engines selected were Wright-branded R-1820-G205 which carried a military designation of R-1820-67/-69 and each turned in opposite directions to counter the naturally-occurring torque effects unique to any engine. Wings were clipped at the ends (ala the North American P-51 Mustang) and the empennage was dominated by the spit twin vertical fins as was found on the original XF5F-1. The cockpit was positioned in the middle of the fuselage and covered with a glazed frame canopy. Vision was reported solid when peering forward and above yet the wing and engine placement no doubt hampered vision below - a common design detriment of twin-engine fighters throughout the war.

Armament options were tossed about during the development of the XP-50. Since heavy caliber air-cooled machine guns were the norm for US aircraft designs of the time, a preliminary armament package of 6 x 12.7mm Browning machine guns was brought forth. This would have a cluster of 4 x 12.7mm guns in the nose assembly and an additional 1 x 12.7mm to a wing. An impressive total of 500 rounds per gun was envisioned. The second proposed armament package was more in line with the future of the quintessential dogfighter and consisted of a battery of 2 x 20mm Hispano-Suiza cannons in the nose along with 2 x 12.7mm machine guns. 60 rounds were to be afforded the cannons. A further 2 x 12.7mm machine guns were intended to be mounted in each wing. Al in all, either weapon formation would have made the XP-50 an aircraft to be reckoned with. To make the Xp-50 a true hybrid fighter-bomber, provision was added for a single 165lb drop bomb under each wing. In an interesting design note, a window was installed on the cockpit floor for the sole use of assisting the pilot in bombing. Unfortunately for the XP-50, none of this armament was ever fitted into the design.
First flight for the XP-50 occurred in February of 1941 and the system passed all crucial performance tests despite the relatively short flight time of just twenty minutes. Successive flights were equally promising until on April 14th, 1941, the aircraft suffered a catastrophic failure of one of the turbosuperchargers forcing the pilot to eject the aircraft and lose it to the waters near Long Island Sound. This no doubt provided a dark stain on the XP-50 and the US Army made moves to secure the Lockheed XP-38 instead.

Despite the setback, the design was reconstituted into yet another new design - the Model G-51. This particular design was to form the basis of the XF7F which would become the F7F Tigercat of United States Marine fame (missing out on World War 2 altogether yet making a splash in the Korean War a few short years later). In any case, the XP-50 was a solid design when compared to other developmental aircraft of the war. Grumman would no doubt recover from the rejection by becoming one of America's best known aircraft firms with the production of the F6F Hellcat, F8F Bearcat and the timeless F-14 Tomcat among other notable systems.
Grumman XP-50 Specifications
National Flag Graphic
United States
Year: 1941
Status: Cancelled
Type: Twin-Engine Fighter Prototype
Manufacturer(s): Grumman - USA
Production: 1
Supported Mission Types
Ground Attack
Close-Air Support
Airborne Early Warning
Electronic Warfare
Aerial Tanker
Passenger Industry
VIP Travel
Business Travel
Special Forces
Crew: 1
Length: 31.89 ft (9.72 m)
Width: 41.99 ft (12.80 m)
Height: 11.98 ft (3.65 m)
Empty Weight: 8,298 lb (3,764 kg)
MTOW: 10,600 lb (4,808 kg)

Installed Power
2 x Wright R-1820-67 / -69 9-cylinder air-cooled radial piston engines developing 1,200 horsepower each.

Standard Day Performance
Maximum Speed: 424 mph (683 kph; 369 kts)
Maximum Range: 1,250 mi (2,011 km; 1,086 nm)
Service Ceiling: 40,000 ft (12,192 m; 7.58 mi)
Rate-of-Climb: 3,800 ft/min (1,158 m/min)

4 x 12.7mm Browning air-cooled machine guns in nose with 500 rounds each gun.
2 x 12.7mm Browning air-cooled machine guns in wings (1 to a wing) with 500 rounds each gun.

2 x 20mm Hispano-Suiza cannons in nose with 60 rounds each.
2 x 12.7mm Browning air-cooled machine guns in nose.
2 x 12.7mm Browning air-cooled machine guns in wings (1 to a wing).

2 x 165lb drop bombs (1 under each wing)

Operators List
United States (cancelled)

Series Model Variants
• Design 34 - Internal Grumman Designation
• G-46A - Internal Grumman Designation
• XP-50 - Single Prototype Model; S/N: 39-2517; fitted with 2 x Wright R-1820-67/-69 series engines; armament proposed but never installed; did not complete full flight testing.
• XP-65 - "Improved" XP-50 Proposal; fitted with 2 x Wright R-2600-10 series engines; never constructed.

Supported Weapon Systems
Graphical image of an aircraft medium machine gun
Graphical image of an aircraft heavy machine gun
Graphical image of an aircrat automatic cannon
Graphical image of an aircraft conventional drop bomb munition

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