Mil Mi-1

Mi-1
Mil Mi-1U
Role	Helicopter
Manufacturer	Mil Moscow Helicopter Plant and other Soviet national plants, WSK PZL-Świdnik,
First flight	20 September 1948
Introduction	1950
Primary user	Soviet Air Force
Produced	1950–1965
Number built	>2,594
Variants	PZL SM-2

The Mil Mi-1 (USAF/DoD reporting name "Type 32",NATO reporting name "Hare") was a Soviet three- or four-seat light utility helicopter. It was the first Soviet helicopter to enter serial production. It is powered by one 575 hp Ivchenko AI-26V radial. It entered service in 1950 and was first seen on the 1951 Soviet Aviation Day, Tushino and was produced for 16 years. More than 1,000 were built in the USSR and 1,594 in Poland, as SM-1.

Mikhail Mil began work on rotary-winged aircraft before 1930, but the Mi-1, his first production helicopter, was begun in 1946, under a designation EG-1. In 1947 Mil became a head of OKB-4 design bureau in Tushino, and works were intensified. A final design was named GM-1 (for Gelikopter Mila). Its design owed much to the Sikorsky S-51 and Bristol 171, with almost identical main rotor to the British machine and similar shafting and clutch. The prototype completed first free flight on 20 September 1948 (pilot Mikhail Baikalov). In 1949 it underwent official state trials. Despite crashes of two prototypes, the design was an overall success, and after further work, was ordered for a production, under a new designation Mi-1, for Mil initials. The production was initially limited—the first series of only 15 machines was ordered on 21 February 1950, in factory No.3 in Moscow. Only after presentation to Joseph Stalin in 1951, the authorities decided to increase production. In 1952–1953, 30 Mi-1 were manufactured in Kazan, and from 1954 a mass production started in Orenburg and from 1956 in Rostov (current Rostvertol). The design was a subject of further improvements during production, mostly increasing reliability. Especially a rotor technology was changing. Period between repair increased to 300 hours in Mi-1T (hence a letter T for trekhsotchasovoi), 600 in Mi-1A, then to 1,000 and 3,000 hours by the end of production.

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