The MI-4 Hound helicopter is a piston-engine aircraft developed for military transport. Approximately 3,000 MI-4 Hounds were built before production ended in 1969. It"s large, four-blade main rotor is mounted on top of the fuselage midsection. The single piston engine is mounted within the nose section. The fuselage is short and oval with a solid rounded nose and stepped-up cockpit. The first model entered into service in 1952. The helicopter was first displayed to the outside world in 1952 at the Soviet Aviation Day in Tushino.