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. 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 gold course, but 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.