Mil Mi-6
The Mil Mi-6 (NATO reporting name Hook), given the article number izdeliye 50 and company designation V-6, was a Soviet/Russian heavy transport helicopter that was designed by the Mil design bureau. It was built in large numbers for both military and civil roles.
Design and development
The Mi-6 resulted from a joint civil-military requirement for a very large vertical-lift aircraft, which could be used to add mobility in military operations as well as assist in the exploration and development of the expansive central and eastern regions of the USSR. Flown for the first time on 5 June 1957, the Mi-6 was the first Soviet turboshaft powered production helicopter.
The R-7 gearbox and rotor head developed for the project have a combined weight of 3200 kg, which is greater than the two turboshaft engines.
Variable-incidence winglets were first mounted on the craft's sides in 1960 to the 30 pre-series units. These wings provide approximately 20% of the lift required during cruise flight.
The Mi-6 was by far the world's largest helicopter when it was designed in 1954–56; with a maximum load capacity of 12,000 kg. It was also the world's fastest helicopter; with a top speed of 300 km/h (190 mph). In its early days, the Mi-6 set many world records, including one for sheer circuit speed at 340 km/h (211 mph). As of 2013, the Mi-6 still holds the FAI record of fastest 5-tonne lift over 1,000 km, in which it flew 284 km/h in 1962.