Mi-8

Mi-8
Mi-8 of Baltic Airlines taking off at Peter and Paul Fortress in Saint Petersburg
Role	Transport helicopter (also, several armed versions)
Design group	Mil Moscow Helicopter Plant
Built by	Kazan Helicopter Plant Ulan-Ude Aviation Plant
First flight	7 July 1961
Introduction	1967
Status	In service
Primary users	Soviet Union (historical) ca. 80 other countries, see Operators below
Produced	1961–present
Number built	>17,000 and production continues today; world's most-produced helicopter
Variants	Mil Mi-8T/Mi-17
Developed into	Mil Mi-14

The Mil Mi-8 (Russian: Ми-8, NATO reporting name: Hip) is a medium twin-turbine helicopter, originally designed by the Soviet Union, and now produced by Russia. In addition to its most common role as a transport helicopter, the Mi-8 is also used as an airborne command post, armed gunship, and reconnaissance platform. Along with the related, more powerful Mil Mi-17, the Mi-8 is among the world's most-produced helicopters, used by over 50 countries. As of 2015, it is the third most common operational military aircraft in the world.

Mikhail Mil originally approached the Soviet government with a proposal to design an all new two-engined turbine helicopter after the success of the Mil Mi-4 and the emergence and effectiveness of turbines used in the Mil Mi-6; but the military argued against a new helicopter, as they were content with the current Mil Mi-4. To counter this, Mikhail Mil proposed that the new helicopter was more of an update to new turbine engines rather than an entirely new helicopter; this persuaded the council of ministers to proceed with production. Due to the position of the engine, this enabled Mikhail Mil to justify redesigning the entire front half of the aircraft around the single engine (designed by Alexander Ivchenko, originally for fixed wing aircraft as all other soviet turbines had been up to that point).

The prototype, which was named V-8, was designed in 1958 and based on the Mil Mi-4 with a larger cabin. Powered by an AI-24 2,010 kW (2,700 shp) Soloviev turboshaft engine, the single engined V-8 prototype had its maiden flight in June 1961 and was first shown on Soviet Aviation Day parade (Tushino Air Parade) in July 1961.

During an official visit to the United States in September 1959, Nikita Khrushchev took a flight in the S-58 presidential helicopter for the first time and was reportedly extremely impressed. On Khrushchev's return, he ordered the creation of a similar helicopter, which was to be ready for the return visit by the American president, to save face. A luxury version of the Mi-4 was quickly created and Khrushchev took an inspection flight, during which Mikhail Mil proposed that his helicopter in development was more suitable. However, it would be necessary to have a second engine for reliability. This gave Mikhail Mil the power under the orders of Khrushchev to build the original two-engined helicopter, which for the first time in Soviet history would need purpose-built turbine engines, rather than those adapted from fixed wing aircraft (as in the Mil Mi-6 and the first prototype V-8) and an entirely new main rotor gear box that would be designed in-house for the first time. In May 1960, the order was given for Mikhail Mil to create his twin engine helicopter. The Sergei Isotov Design Bureau accepted the task of creating the engines.

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