XF-11 Reconnaissance Aircraft

XF-11 reconnaissance aircraft in flight

The Hughes XF-11 was designed to be a fast, long-range reconnaissance aircraft for the U.S. Army. The XF-11 was a tricycle-gear, twin-engine, twin-fuselage, all-metal monoplane with a pressurized central crew nacelle. The front and rear propellers on each engine were counter-rotating. This unusual design increased performance and stability but added a great deal of mechanical complexity.

The Army originally ordered 100 XF-11s, but the order was cancelled at the end of World War II, leaving Hughes with two prototypes.

Howard Hughes was flying the first prototype when it crashed on July 7, 1946, on its maiden flight. An oil leak caused the right engine propeller controls to malfunction, so the rear propeller reversed its pitch, making aircraft difficult to control. Hughes tried to make an emergency landing on the Los Angeles Country Club's golf course, but about 300 yards short of the course, the aircraft suddenly lost altitude and clipped three houses. The third house was completely destroyed by the fire resulting from the crash and Hughes was badly hurt.

The second prototype was fitted with conventional propellers. After Hughes had recovered from his injuries, he flew it successfully April 5, 1947. However, it was lacking in low-speed stability so the Air Force ordered the Boeing RB-50 (a reconnaissance version of the B-50 bomber), which had similar long-range photoreconnaissance capability and was less expensive.

Specifications
First flight: July 7, 1946
Model number: XF-11
Classification: Reconnaissance aircraft
Length: 65 feet 5 inches
Wingspan: 101 feet 4 inches
Height: 23 feet 2 inches
Wing area: 983 square feet
Empty weight: 37,100 pounds
Max. takeoff weight: 58,300 pounds
Max. speed: 450 mph
Range: 5,000 miles
Service ceiling: 44,000 feet
Power: Two Pratt & Whitney 3,000-hp R-4360-31 radial air-cooled, 28-cylinder engines with a Hamilton-Standard eight-blade, counter-rotation, superhydromatic propeller on each engine
Accommodation: Pilot and navigator/photographer