Kawasaki Ki-64

The Kawasaki Ki-64, given the Allied code name Rob, was a one-off prototype of an experimental heavy single-seat fighter. Its unusual layout placed two Kawasaki Ha-40 engines in tandem, one in the nose and one behind the cockpit, joined by a drive shaft as the Ha-201 power unit and turning two contra-rotating three-bladed propellers. The wing surfaces served as the radiators for the water-cooled engines. It first flew in December 1943, but on the fifth flight the rear engine caught fire and the aircraft was damaged in the emergency landing. The project was abandoned in mid-1944 in favour of more promising work, though the airframe survived the war and parts of its cooling system were sent to Wright Field for study.