Hughes XR-11 / XF-11 Long-Range Photographic Reconnaissance Aircraft Prototype

The Hughes XF-11 reconnaissance-minded platform only saw two prototypes completed - the first crashing into the suburb of Beverly Hills with Howard Hughes at the controls.

Updated: 5/11/2016; Authored By Staff Writer; Content ©www.MilitaryFactory.com

Though only achieving prototype form, the XF-11 was one of the darling designs of famed American aviator Howard Hughes. Looking very much like an oversized Lockheed P-38, the twin-boom XF-11 was designed to fulfill a United States military requirement for a long-range photographic reconnaissance fighter. The project progressed with great potential until a disastrous crash of Prototype 1 in the suburbs of Beverly Hills (nearly taking the life of Hughes himself) effectively caused the cancellation of the entire project. The XF-11 would face off with Republic's offering of the XF-12 "Rainbow" only to see neither design chosen at project's end.

The XF-11 was of a traditional twin-boom design, popularized in other forms such as the Northrop P-61 Black Widow and the aforementioned Lockheed P-38 Lightning. The first of two prototypes featured contra-rotating propeller systems on each engine, offering up a great deal of power and performance potential at the cost of increased maintenance and production times. The X-11 featured a powered tricycle landing gear system which proved successful in other designs during the Second world War. The fuselage was constructed of all metal with a two-man crew - the pilot and a radio operator - in a center-fuselage nacelle with complete cabin pressurization for high-altitude capability. Pratt & Whitney brand engines were selected to power the design and these powerplants would turn two four-bladed propeller systems with variable pitch settings. With the Beverly Hills crash blamed on engine failure, the second XF-11 prototype was engineered with traditional non-contra-rotating propeller blade systems.

By all respects, the XF-11 performed admirably well considering the dramatic series of setbacks to the project. Stability and control at high speeds was especially noteworthy though exception was made to the low-altitude stability and performance the system encouraged. A complicated aircraft to fly when compared to others of this type, the XF-11 was nonetheless a capable design in most respects.

Pitted against the Republic XF-12, the XF-11 was deemed as too costly to maintain and produce along with the complications inherent in the system's design. Even with the XF-12 having an edge, the United States Air Force ultimately went with the Boeing produced RB-50 reconnaissance aircraft, citing its respectable range and reconnaissance capabilities equal to that of either XF offering with a lesser price tag.

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Hughes XR-11 / XF-11 Technical Specifications

Service Year: 1946
Type: Long-Range Photographic Reconnaissance Aircraft Prototype
National Origin: United States
Manufacturer(s): Hughes Aircraft - USA
Production Total: 2

Structural (Crew Space, Dimensions and Weights)

Operating Crew (Typical): 2
Overall Length: 65.42 feet (19.94 meters)
Overall Width: 101.35 feet (30.89 meters)
Overall Height: 23.16 feet (7.06 meters)

Weight (Empty): 37,038 lb (16,800 kg)
Weight (MTOW): 58,202 lb (26,400 kg)

Installed Power and Standard Day Performance

Propulsion: 2 x Pratt & Whitney R-4360-31 radial piston engines developing 3,000 horsepower each.

Maximum Speed: 447 mph (720 kph; 389 knots)
Maximum Range: 4,971 miles (8,000 km)
Service Ceiling: 44,012 feet (13,415 meters; 8.34 miles)

Armament / Mission Payload

None.

Global Operators / Customers

United States (cancelled)

Model Variants (Including Prototypes)

XF-11 - Original Series Designation; 2 examples produced with the first offering featuring contra-rotating blades and the second with traditional propeller blade assemblies.

XR-11 - Later Designation