a red Mil Mi-4 „Hound“ utility helicopter with Aeroflot titles and civilian registration CCCP-31449. Comparable in dimensions with the US-build Sikorsky S-55 (or H-19 „Chickasaw“), the Mil 4 could carry twice of the load. Powered by a 1694PS – Shvezov ASch-82, this type entered service in May 1952 and soon became the standard utility helicopter of the Soviet Army. Later variants included an anti-submarine or ground-attack helicopter, while civil versions were used by Aeroflot with an accomodation up to 16 passengers. Between 1953 and the end of production in 1969, more than 3500 examples were build in Russia, Chinese production ended in 1980 after 1000 examples completed. By 1968 the ageing Mi-4 was replaced by the larger Mil Mi-8 „Hip“, an advanced medium twin-turbine utility transport helicopter.