Hughes—XF-11 US Air Force: Aircraft History
Hughes—XF-11

No purpose-built photo-reconnaissance aircraft flew during World War II, but among those designed for the role was the mighty Hughes XF-11 (later redesignated XR-11). This had been developed from the private-venture Hughes D-2, which had first flown at Harper Lake on 20 June 1943. Dissatisfied with this aircraft, which was destroyed in a hangar fire in November, Hughes designed a more sophisticated aircraft, the D-5. With the USAAF designation XF-11, the aircraft was developed purely for the long-range high-altitude reconnaissance role, and was intended as a replacement for the Lockheed F-5 (P-38), which it resembled in configuration. The slender wing mounted two long tailbooms and a central nacelle where the pilot and cameras were accommodated. The tailbooms continued forward of the wing to mount 3,000-hp Pratt & Whitney R-4360-31 engines.

The first prototype (44-70155) was fitted with contra-rotating propellers, and flew for the first time on 7 July 1946. Although showing sufficient promise to warrant an order for 98 production F-11s, the program was terminated when the first aircraft crashed on account of one of the contra-rotating propellers going into reverse pitch. The pilot, Howard Hughes himself, was almost killed in the ensuing crash. When the second aircraft (44-70156) flew in April 1947, it had standard four-bladed propellers.