Mi-8 MT Helicopter Technical Specifications
- Crew – 3 people
- Engine – 2 x TV2-117AT
- Power – 2200 hp
- Main rotor diameter-21.29 m
- Empty helicopter weight-6625 kg
- Maximum take-off weight-13,000 kg
- Full load weight-4000 kg
- Number of paratroopers-up to 24 people
- Maximum speed at altitude/near the ground-250 / 220 km / h
- Practical ceiling-5000 m
- Maximum range – 580 km
- Armament: 1 x 12.7 mm YakB machine gun or 7.62 mm GSHG machine gun;
- Combat load – up to 4000 kg on 6 suspension units: 6 UB-32-57 NAR S-5 units; 4 ATGM 9M17 “Phalanx” or air bombs of 100, 250 and 500 kg caliber.
Mi-8 MT Helicopter Details
In the late 1950s, the Soviet Union began work on the creation of second-generation helicopters with gas turbine engines. In 1957, the Mil Design Bureau began developing a fundamentally new V-8 helicopter with a payload capacity of 1.5-2 tons, equipped with a helicopter version of the AI-24V gas turbine engine, to replace the Mi-4 multi-purpose helicopter. At the same time, it was supposed to use the Mi-4 helicopter’s chassis, transmission, propellers and other units and systems. The development of the new helicopter was initiated by the Ministry of Civil Aviation, supported later by the Air Force Command.
On February 20, 1958, the USSR Council of Ministers issued a decree on the creation of a new V-8 helicopter in the Mil Design Bureau, and the following year its working design began. The development of the helicopter was supervised by Deputy Chief Designer V. A. Kuznetsov. While working on this helicopter, it was decided to switch from a single engine to a twin-engine vehicle. The twin-engine powerplant made it possible to increase not only its load capacity, but also provided high reliability, sufficient to perform horizontal flight without reducing if one of the engines failed. Especially for the V-8 helicopter, new TV2-117 engines were designed by the Izotov Design Bureau, which developed a take-off power of 1500 hp and had relatively high specific performance.
The V-8A twin-engine passenger 20-seat helicopter made its first flight on September 17, 1962. In the course of subsequent state tests, the B-8A helicopter underwent significant improvements: the four-bladed main rotor was replaced with a five-bladed one, which reduced the level of vibrations; the steering screw with wooden blades was replaced with a new one, on a gimbal suspension with all-metal blades; the single-chamber landing gear struts were replaced with two-chamber ones with pneumatic-oil shock absorbers; the power plant received an automatic engine control system that ensures their synchronization and maintains the speed of rotation of the main rotor within the specified limits, and a four-channel autopilot was included in the control system.
The modified helicopter, designated B-8AT, was developed for the Soviet Army in an amphibious transport version with a cargo cabin with folding seats for 20 paratroopers and a cargo hatch for loading various military equipment. In 1963, the V-8AT helicopter was submitted to state tests. Compared to the Mi-4 helicopter, the new helicopter had higher flight characteristics and twice the payload capacity. In November 1964, after successful flight tests, it was decided to mass-produce a passenger helicopter under the designation ” Mi-8P “and an amphibious transport helicopter under the designation” Mi-8T ” at the Kazan Helicopter Plant, where since 1965 more than 7,300 Mi-8 and then Mi-17 helicopters were built (in the export version). Since 1970, Mi-8 and Mi-17 helicopters have been produced at the Ulan-Ude Aviation Plant, where more than 3,800 helicopters have been built.
In the mid-1960s, an even more powerful (2,200 hp) TVZ-117 gas turbine helicopter engine was developed, which passed state tests in 1972. Its appearance led to the creation of a deep modification of the Mi – 8MT helicopter, which could initially carry a load of up to 3000 kg, and on an external suspension (in the Mi-8MTV-2 version) – up to 4000 kg. This made it possible to significantly expand the range and weight of the arsenal of the combat vehicle. The upgraded Mi-8 helicopter received more powerful TVZ-117MT engines with dust protection devices. In addition to the new engines, it was also equipped with an AI-9V auxiliary power plant, which is necessary for starting engines using compressed air, and the location of the tail rotor was changed. Other design changes were also made to improve the combat and operational characteristics of the Mi-8. So, he received protected fuel tanks, which excluded fires and explosions of tanks-even when hit by large-caliber bullets. At the same time, the tail rotor control cables were separated; the main lines of oil and hydraulic systems were shielded, duralumin pipes were replaced with metal-braided hoses, which increased the survivability of the machine. Due to the strengthening of the nose parts of the main rotor blades, they turned out to be more resistant to mechanical damage when colliding with small stones and sand raised from the ground, which increased its service life. Flight tests of the Mi-8MT, built in Kazan, began on August 17, 1975, and in 1977, this helicopter was put into mass production. With the same engines as the Mi-24 and close firepower, the Mi-8MT was a ton lighter, which affected its better maneuverability and rate of climb. By the number of built (more than 13,000) Mi-8 helicopters and their development Mi-17, produced in more than 30 main modifications, significantly exceed all foreign helicopters of this class, while more than 3,000 Mi-8 and Mi-17 helicopters of various modifications were delivered abroad.
The upgraded Mi-8MT amphibious transport helicopter was designed to combat armored ground, surface, mobile and stationary small-sized targets; to defeat enemy personnel; transport troops, cargo, wounded, and perform search and rescue operations. This helicopter was produced in several military versions: Mi-8AM and Mi-8MTV with various equipment and weapons; as well as in the civilian version – Mi-8MTB-1A.
The Mi-8MT helicopter was designed according to a single-rotor scheme with a five-bladed main and three-bladed tail rotors and a three-support fixed landing gear. Attachment of the main rotor blades is articulated (with vertical, horizontal and axial hinges), and the tail rotor blades are combined (horizontal and axial), cardan type. The main rotor blades are all – metal. The helicopter fuselage is a frame structure. A three-seat crew cabin was located in the bow. The crew consisted of: commander-left pilot; the second pilot, who performed the functions of the operator of NUR and ATGM when searching for targets, launching and pointing guided missiles at the target, as well as the duties of the navigator and flight mechanic, who also performed the functions of the shooter of the aft and bow machine gun installations. The cabin glazing provided a good view, and the right and left sliding blisters were equipped with emergency release mechanisms. In the central part, there was a cargo cabin designed to carry cargo weighing up to 4 tons and equipped with folding seats for 24 passengers, as well as nodes for attaching 12 stretchers.
In the transport version, the cargo cabin had a cargo hatch with flaps that increase the length of the cabin, and with a central sliding door with an emergency release mechanism; mooring units and an electric bucket were located on the floor of the cargo cabin, and an electric bucket boom was located above the door. The powerplant consisted of two TV2-117AT free-flow gas turbine engines mounted on top of the fuselage and closed by a common hood with opening flaps. If one of the engines failed in flight, the other engine automatically reached increased power, while horizontal flight was performed without reducing altitude. The Mi-8 was equipped with a four-channel AP-34 autopilot, which provides roll, pitch and direction stabilization, as well as flight altitude (± 50 m). Navigation and flight instruments and radio equipment in all versions of the helicopter made it possible to fly at any time of the day and in difficult weather conditions. Helicopters of various modifications differed significantly in the composition of equipment. On military versions of the Mi-8MT, an infrared (IR) jamming station “Lipa” was installed; a screen-exhaust device for suppressing IR radiation from engines; containers with a passive jamming system; the crew cabin received reservations. These Mi-8MT helicopters were equipped with a single-barreled 12.7-mm A-12.7 machine gun or a 12.7-mm YakB-12.7 four-barreled machine gun or a 7.62-mm GSHG-7.62 four-barreled machine gun mounted in a forward mobile installation; built-in holders on shaped pylons on the sides of the fuselage for installing up to six blocks of UB-32-57 unguided S-5 aircraft missiles or bombs with a caliber of 100, 250 and 500 kg, and also placed on top of up to four ATGM 9M17 “Phalanx” on beam holders. Containers with machine guns or cannons could also be hung on pylons, and machine guns and grenade launchers could be mounted on pins in blisters and side openings of the cargo cabin.
Over its 50-year history, Mi-8 helicopters have taken part in a large number of local military conflicts, including in Afghanistan and in both Chechen wars. Mi-8s flew at extremely low altitudes and high in the mountains, were based outside the airfield network and landed in hard-to-reach places with minimal maintenance, each time proving their high reliability and efficiency. Currently, the Mi-8 multi-purpose helicopter, created in the middle of the last century, is one of the most popular in its class and will continue to be in demand in the Russian and global aviation equipment market for many years to come.