Kawasaki Ki-64

The Kawasaki Ki-64 was a one-off prototype of an experimental heavy, single-seat fighter. It had two unusual design features. First, it had two Kawasaki Ha-40 engines in tandem, one in the aircraft nose and the other behind the cockpit, both connected by a drive shaft. This combination drove two, three-bladed, contra-rotating propellers. The second feature was using the wing surface as a radiator for the water-cooled engines. The aircraft first flew in December 1943. During the fifth flight, the rear engine caught fire, and, while the aircraft made an emergency landing, it was damaged. The aircraft was subsequently abandoned in mid-1944 in favour of more promising projects. The airframe survived the war, and parts of the unique cooling system were sent to Wright Field for examination.