In the second half of the 1950s, the Mil Experimental Design Bureau-329 (OKB-329) began work on a programme of major modernization of the light multi-purpose Mi-1 helicopter. Among the changes considered was the possibility of replacing the piston engine with a new turbine powerplant. It was also assumed that the dimensions of the new design would remain the same as the Mi-1, while significantly increasing the cabin capacity (8 people).
From several concepts, the most promising “classic” configuration (single-rotor with tail rotor) was selected, powered by two turbine engines connected to a common reduction gearbox. The engine compartment was planned above the cabin, in the upper part of the fuselage. This made it possible to gain additional space for passengers or cargo. The twin-engine layout also increased flight safety in case of failure, as it was assumed that flight and safe landing on one engine would be possible. The new helicopter project was named V-2. The only problem with the new design was the lack of a suitable powerplant.
Design of the new engine began at the Klimov Design Bureau in Leningrad in 1959-60, under the direction of chief designer S. P. Izotov. A small turbine engine, the GTD-350, was developed there, modelled on the American helicopter engine Allison 250. In 1963, the GTD-350 passed state trials, although it was inferior to similar foreign designs in terms of technical parameters.
At the end of May 1960, the Mil Experimental Design Bureau received an official government order for the new helicopter. Both military and civilian aviation were interested in the new design.
During the design of the V-2 helicopter, efforts were made to use as many components as possible from the production Mi-1. In practice, this proved impossible. At the end of September 1961, the V-2 prototype made its first hover and low-speed flight. A month later, state trials began. Test flights proceeded without any problems, and the V-2 proved to be a very successful design. The military were interested in a transport and medical evacuation version, while civilian aviation favoured an agricultural variant. In September 1963, the State Commission decided to put the helicopter into series production under the designation Mi-2.
In September 1962, the first V-2 prototype was shown to a Polish government delegation. At that time, the possibility of producing it in Poland began to be considered. To this end, preliminary preparations started at the WSK aircraft factory in Swidnik at the end of 1963. In January 1964, an official agreement was signed for the transfer of the licence to produce the Mi-2 helicopter and the GTD-350 engine with its reduction gearbox. The helicopter was to be manufactured at the Swidnik factory, and the engine at the plant in Rzeszow.
At the end of August 1965, the first Mi-2 assembled from Russian-supplied parts made its maiden flight at the factory airfield in Swidnik; in November of the same year, a helicopter entirely manufactured in Poland took to the air. Large-scale series production began and continued until the early 1990s. A total of 5,418 Mi-2 helicopters were produced, the majority of which were delivered to the USSR, some were exported to 10 countries, and some were purchased by Polish military and civilian aviation (passenger, medical, maritime rescue). The number of foreign operators grew as a result of numerous resales.
Several attempts were made to modernize the Mi-2; interesting upgrade proposals emerged both in Poland and in the USSR. However, the lack of a suitable turbine engine of greater power stood in the way. M. L. Mil and his successor M. N. Tishchenko repeatedly tried to persuade engine designers in the USSR to develop a new low-power turbine engine, but these efforts were unsuccessful. In Poland, modernization was undertaken by fitting the American Allison 250 helicopter turbine engine. The new helicopter was named PZL “Kania.” Its performance improved significantly
compared to the Mi-2.
The first versions used by the Polish armed forces were: Mi-2T – transport with the option of rapid conversion to a medical evacuation role, capable of carrying up to 700 kg of cargo or 6-8 people; Mi-2P – passenger version carrying 6 people; Mi-2Sz (Mi-2U, UMi-2) – training version with dual controls, adapted for instrument flight training.
At the turn of the 1960s and 1970s, Polish military specialists analysed the use of helicopters by the American Army in the Indochina War. American experience revolutionized views on the use of helicopters on the battlefield, which proved to be not only an excellent transport and assault asset but also an extremely effective fire support weapon, capable of engaging tanks as well.
In 1970 in Poland, military specialists conducted an analysis of the possibilities of arming the Mi-2. As a result, it was decided to fit the helicopter with a single fixed 23 mm cannon mounted on the lower left side of the fuselage, and four machine guns suspended on the sides (Mi-2US) or two launchers with 32 unguided rockets (Mi-2URN). At the same time, similar trials were being conducted in the USSR.
Concurrently, trials began to adapt the Mi-2 for anti-tank warfare, equipping it with 4 launchers for wire-guided “Malyutka M” anti-tank missiles of Soviet design.
The new helicopter version was designated Mi-2 URP (Armed – Anti-Tank Rockets). Missile firing trials were conducted in 1972 and early 1973. In 1977, Mi-2URP helicopters were used during Warsaw Pact military exercises.
The Mi-2URP was armed with 1 x 23 mm cannon mounted under the lower left side of the fuselage, 2 flexible 7.62 mm machine guns in the sliding side windows of the transport cabin, and 4 x 9M14M “Malyutka M” anti-tank guided missiles on launchers on both sides of the fuselage,
which also carried 4 spare missiles.
The missile was guided to the target observed by the operator using the “three-point” method: eye-missile-target. To improve missile guidance, an optical sight was tested, but helicopter vibrations made proper target observation impossible. The most reliable means of steering the missile remained the observer’s eye and hand operating the control joystick, which sent guidance commands via wire.
In the early 1980s, trials began on a Mi-2 version adapted for engaging aerial targets, designated Mi-2URS. It was armed with 4 “Strela M” guided missiles (man-portable air defence system), which homed in on infrared radiation sources. Once again, helicopter vibrations caused problems with the use of such armament. Consequently, the Mi-2URS was not accepted into service. In the second half of the 1980s, some Mi-2URP helicopters were fitted with “Strela M” missiles, also known as “Gad,” suspended beneath the “Malyutka M” anti-tank missile launchers. This produced the last armed helicopter version, designated Mi-2URP-G.
The first Mi-2 entered Polish military aviation service in 1967. Two years later, the fleet had grown to 34 aircraft. In 1985, the Polish military aviation had 270 Mi-2 helicopters of various versions in service. Many of them continue to serve in the Polish armed forces.
| Rotor diameter | 14.56 m |
| Fuselage length | 11.94 m |
| Takeoff weight | 3550 kg |
| Maximum speed | 185 km/h |
| Ceiling | 4000 m |
| Range | 355 km |
| Armament | described in text |
| Engine | two GTD‑350 turboshaft engines, 400 hp each |
