MOSCOW, November 26 - RIA Novosti. In the north of the Krasnoyarsk Territory, a Mi-8 helicopter crashed, as a result of which, according to preliminary data, 12 people were killed.

The Mi-8 is a multifunctional helicopter, the scope of which is expanding due to constant modernization and the possibility of equipping it with a wide range of additional equipment to perform various tasks. The helicopter can be used in a wide range of conditions and temperatures (from -50 to +50 degrees Celsius), easy to operate and maintain.

The development of the V-8 (Mi-8) helicopter began at the Design Bureau named after M.L. Mil (now OAO Moscow Helicopter Plant named after M.L. Mil, part of the Russian Helicopters holding) in May 1960 to replace the well-proven Mi-4 multi-purpose piston helicopter. The Mi-8 was created as a deep modernization of the Mi-4 with a gas turbine engine. The helicopter was developed simultaneously in two versions: passenger Mi-8P and transport Mi-8T.

The first prototype of the new helicopter (with one engine and a four-blade main rotor) took off in July 1961, the second (with two engines and a five-blade propeller) - in September 1962, the first flight of an experienced helicopter took place in 1962.

Serial production of the Mi-8 began in 1965 at Kazan Helicopter Plant OJSC and Ulan-Ude Helicopter Plant OJSC.

Seven world records were set on Mi-8 helicopters in 1964-1969 (mostly by female helicopter pilots).

The Mi-8 surpasses the Mi-4 in maximum payload capacity by 2.5 times and in speed by 1.4 times. The transmission of the Mi-8 helicopter is similar to the Mi-4 helicopter.

The helicopter is made according to a single-rotor scheme with a tail rotor, two gas turbine engines and a tricycle landing gear.

All-metal rotor blades. They consist of a hollow spar pressed from an aluminum alloy. All main rotor blades are equipped with pneumatic spar damage alarm. Powerful hydraulic boosters are used in the control system. The Mi-8 is equipped with an anti-icing system that operates in both automatic and manual modes. The external suspension system of the helicopter allows you to carry cargo weighing up to 3 tons.

If one of the engines fails in flight, the other engine automatically switches to increased power, while level flight is performed without lowering the altitude. The Mi-8 is equipped with an autopilot that provides roll, pitch and yaw stabilization, as well as a constant flight altitude. The navigation and flight instruments and radio equipment that the helicopter is equipped with make it possible to fly at any time of the day and in adverse weather conditions.

The helicopter is mainly used in transport and passenger versions. In the passenger version (Mi-8P), the helicopter is equipped to carry 28 passengers.

The military version of the Mi-8T has pylons for hanging weapons (unguided rockets, bombs). The next military modification of the Mi-8TV has reinforced pylons for suspension a large number weapons, as well as a machine gun in the bow of the cabin.

Mi-8MT is a modification of the helicopter, which was the logical conclusion of the transition from a transport to a transport-combat helicopter. More modern TVZ-117 MT engines were installed with an additional AI-9V gas turbine unit and a dust protection device at the air intake inlet. To combat surface-to-air missiles, there are systems for dispersing hot engine gases, shooting false thermal targets and generating pulsed IR signals. In 1979-1988, the Mi-8MT helicopter took part in the military conflict in Afghanistan.

The Mi-8 can be used to solve a variety of tasks: for fire support, suppression of firing points, delivery of troops, transportation of ammunition, weapons, cargo, food, medicines, evacuation of the wounded and the dead.

The Mi-8 is the most widespread transport helicopter in the world.

According to the number of modifications, the Mi-8 is the world record holder. There are more than 100 of them. Modifications were created at the M.L. Mile, at Kazan and Ulan-Ude plants, repair enterprises, directly in military units and Aeroflot detachments, as well as abroad during operation.

Tactical and technical characteristics of the helicopter:

Crew - 3 people.

The maximum takeoff weight is 13,000 kg.

GTE engine Klimov TV3-117 - 2.

Power - 2 to 1620 kW.

Length - 18.424 / 25.352 m.

Height - 4.756 / 5.552 m.

The maximum speed is 250 km/h.

The practical flight range is 950 km.

Practical ceiling - 5000 m.

Payload - up to 24 soldiers or 12 stretchers with accompanying or 4000 kg of cargo.

GENERAL CHARACTERISTICS OF THE Mi-8T HELICOPTER

1. GENERAL INFORMATION ABOUT THE HELICOPTER

The Mi-8 helicopter is designed to transport various cargoes inside the cargo compartment and on an external sling, mail, passengers, as well as for construction, installation and other work in hard-to-reach areas.

Rice. 1.1. Mi-8 helicopter (general view)

The helicopter (Fig. 1.1) is designed according to a single-rotor scheme with a five-bladed main rotor and a three-bladed tail rotor. The helicopter is equipped with two TV2-117A turboprop engines with a takeoff power of 1500 hp. each, which ensures high flight safety, since flight is possible even if one of the engines fails.

The helicopter is operated in two main versions: passenger Mi-8P and transport Mi-8T. The passenger version of the helicopter is designed for interregional and local transportation of passengers, luggage, mail and small cargo. It is designed to carry 28 passengers. The transport option provides for the transportation of goods weighing up to 4000 kg or passengers in the amount of 24 people. At the request of the customer, the passenger cabin of the helicopter can be converted into a cabin with increased comfort for 11 passengers.

Passenger and transport versions of the helicopter can be converted into a sanitary variant and into a variant for operation with an external sling.

The helicopter in the sanitary version allows you to transport 12 bedridden patients and an accompanying medical worker. In the variant for operation with an external sling, bulky cargo weighing up to 3000 kg is transported outside the fuselage.

For helicopter flights over long distances, one or two additional fuel tanks are installed in the cargo compartment.

The existing versions of the helicopter are equipped with an electric winch, which allows lifting (lowering) loads weighing up to 150 kg with the help of an onboard boom, and also, in the presence of a chain hoist, pulling wheeled loads weighing up to 3000 kg into the cargo compartment.

The helicopter crew consists of two pilots and a flight engineer.

When creating the helicopter, special attention was paid to high reliability, efficiency, ease of maintenance and operation.

Flight safety on the Mi-8 helicopter is ensured by:

Installation of two TV2-117A(AG) engines on the helicopter, reliable operation of these engines and the VR-8A main gearbox;

The ability to fly in the event of a failure of one of the engines, as well as to switch to the autorotation mode (self-rotation of the main rotor) in case of failure of both engines;

The presence of compartments isolating the engines and the main gearbox with the help of fireproof partitions;

Installation of a reliable fire-fighting system that ensures fire extinguishing in case of its occurrence both simultaneously in all compartments and in each compartment separately;

Installation of redundant units in the main systems and equipment of the helicopter;

Reliable and effective anti-icing devices for the main and tail rotor blades, engine air intakes and cockpit windshields, which allows you to fly in icing conditions;

Installation of equipment that ensures simple and reliable piloting and landing of a helicopter in various meteorological conditions;

The drive of the main units of the systems from the main gearbox, ensuring the operability of the systems in the event of an engine failure:

The ability to quickly leave the helicopter after landing by passengers and crew in emergency cases.

2. MAIN DATA OF THE HELICOPTER

flight data

(transport and passenger options)

Takeoff weight (normal), kg............. 11100

Maximum flight speed (instrument), km/h, 250

Static ceiling, m .............................. 700

Cruise IAS at altitude
500 m, km/h ………………………………………………220

Economic flight speed (instrument), km/h. 120

fuel 1450 kg, km ............................ 365

version with refueling 2160 kg, km. . .620

Flight range (at an altitude of 500 m) in the ferry
variant with refueling 2870 kg, km... 850

Flight range (at an altitude of 500 m) with refueling
fuel 2025 kg (suspended tanks of increased
capacity), km ............................................... .. 575

Flight range (at an altitude of 500 m) in the ferry
version with refueling 2735 kg (suspended tanks

increased capacity), km .... 805

Flight range (at an altitude of 500 m) in the ferry
version with refueling 3445 kg (suspended tanks

increased capacity), km .... 1035

Note. Flight range calculated with 30 minutes remaining fuel after landing

Geometric Data

Helicopter length, m:

without main and tail screws ................. 18.3

with rotating main and tail rotors …25.244

Helicopter height, m:

without tail rotor ......................................... 4.73

with rotating tail rotor ................. 5.654

Distance from the tip of the main rotor blade to
tail boom in the parking lot, m ..................... 0.45

Distance from the ground to the bottom of the fuselage

(clearance), m .............................................. ...... 0.445

The area of ​​the horizontal plumage, m 2 ... .. 2

Helicopter parking angle .................. 3°42"

Fuselage

Cargo cabin length, m:

without cargo flaps .............................. 5.34

with cargo doors at the level of 1 m from the floor 7.82

Cargo cabin width, m:

on the floor................................................ ... 2.06

for heating ducts ........................... 2.14

maximum ........................................ 2.25

Cargo cabin height, m ​​.................. 1.8

The distance between the power beams of the floor, m ... 1.52

Escape hatch size, m…………………… 0.7 X1

Gauge of loading ladders, m .............. 1.5±0.2

Passenger cabin length, m .............. 6.36

Passenger cabin width (on the floor), m... 2.05

Passenger cabin height, m ​​1.8

Seat pitch, m .............................................. .... 0.74

Passage width between chairs, m... 0.3

Wardrobe dimensions (width, height, depth), m 0.9 X1.8 X 0.7
» sliding door (width, height), m. . 0.8X1.4
» opening, along the rear entrance door in the passenger

variant (width, height), m.......... 0.8 X1>3

The size of the emergency hatches in the passenger

variant, m .................................................. 0, 46X0.7

Crew cabin size, m .............. 2.15 X2.05 X1.7

Adjustment data

The angle of installation of the main rotor blades (according to the propeller pitch indicator):

minimum................................................. 1°

maximum ........................................ 14°±30"

Angle of deflection of trimmer plates of propeller blades -2 ±3°

» installation of tail rotor blades (at r=0.7) *:

minimum (left pedal to the stop) ................... 7 "30" ± 30"

maximum (right pedal to the stop)………….. +21°±25"

* r- relative radius

Weight and centering data

Takeoff weight, kg:

maximum for transport option …….. 11100

» with load on external sling …………… 11100

transport option ........................ 4000

on an external sling ............................... 3000

passenger variant (person).......... 28

Empty helicopter weight, kg:

passenger variant............................ 7370

transport "................................ 6835

Service load mass, including:

crew weight, kg .............................. 270

» oil, kg .............................................. ............. 70

mass of products, kg .............................................. 10

» fuel, kg .................................................. ........... 1450 - 3445

» commercial load, kg .............................. 0 - 4000

Empty helicopter centering, mm:

transport option ................................................ +133

passenger » ....................................... +20

Permissible centering for a loaded helicopter, mm:

front ................................................. ................. +370

rear ................................................. ................... -95

3. AERODYNAMIC AND GEOMETRIC CHARACTERISTICS OF THE HELICOPTER

According to the aerodynamic design, the Mi-8 helicopter is a fuselage with a five-bladed main rotor, three-bladed tail propellers and fixed landing gear.

The main rotor blades are rectangular in plan with a chord equal to 0.52 m. The rectangular shape in terms of aerodynamics is considered worse than others, but it is easy to manufacture. The presence of trimmer plates on the blades allows you to change their torque characteristics.

The blade profile is the most important geometric characteristic of the main rotor. On the helicopter, various profiles along the length of the blade are selected, which significantly improves not only the aerodynamic characteristics of the main rotor, but also the flight properties of the helicopter. From the 1st to the 3rd section, the NACA-230-12 profile is used, and from the 4th to the 22nd - the NACA-230-12M profile (modified) *. For the NACA-230-12M airfoil, the number Mcr = 0.72 at an angle of attack of zero lift. With an increase in the angles of attack a ° (Fig. 1.2), Mcr also decreases at the most favorable angle of attack, at which the lift coefficient C y \u003d 0.6, Mcr \u003d 0.64. In this case, the critical speed in the standard atmosphere above sea level will be:

V KP == a Mcr = 341 0.64 = 218 m/s, where a is the speed of sound.

Consequently, at the ends of the blades, it is possible to create a speed of less than 218 m/s, at which shock waves and wave resistance will not appear. With an optimal main rotor speed of 192 rpm, the peripheral speed of the ends of the blades will be:

U \u003d wr \u003d 2 prn / 60 \u003d 213.26 m / s, where w is the angular velocity;

r is the radius of the circle described by the end of the blade.

Rice. 1.2. Change in the lift coefficient C y from the angles of attack a° and the M number of the NACA-230-12M airfoil

This shows that the circumferential speed is close to critical, but does not exceed it. The rotor blades of a helicopter have a negative geometric twist that varies with linear law from 5° at the 4th section to 0° at the 22nd. There is no twist in the section between the 1st 4th sections and the installation angle of the blade sections in this section is 5°. The twist of the blade by such a large amount significantly improved its aerodynamic properties and flight characteristics of the helicopter, and therefore more evenly distributed lifting force along the length of the blade.

* The compartment from the 3rd to the 4th section is transitional. Main rotor blade profile - see fig. 7.5.

The propeller blades have both absolute and relative profile thicknesses. The relative profile thickness c is 13% in the butt, in the section from r = _0.23 to 7 = 0.268-12%, and in the section from r = 0.305 to the end of the blade - 11.38%. Reducing the thickness of the blade towards its end improves the aerodynamic properties of the propeller as a whole by increasing the critical speed and Mcr of the end parts of the blade. Reducing the thickness of the blade towards the end leads to a decrease in drag and a decrease in the required torque.

The main rotor of the helicopter has a relatively large fill factor - 0.0777. This coefficient makes it possible to create high thrust with a moderate propeller diameter and thereby keep the blades in flight at small setting angles, at which the angles of attack are closer to the most advantageous in all flight modes. This made it possible to increase the efficiency of the propeller and move the stall at high speeds.

Rice. 1.3. Helicopter rotor polar in hover mode: 1 - without ground effect; 2 - with the influence of the earth.

The aerodynamic characteristic of the main rotor of the helicopter is presented in the form of its polar (Fig. 1.3), which shows the dependence of the thrust coefficient Cp and the torque coefficient t cr on the total pitch of the main rotor<р. По поляре видно, что чем больше общий шаг несуще­го винта, тем больше коэффициент крутящего момента, а следовательно, больше коэффициент тяги. При наличии «воздушной подушки» тяга несущего винта будет больше, чем без нее при том же шаге винта и коэффициенте кру­тящего момента.

The tail rotor blades are rectangular in plan with a NACA-230M profile and do not have a geometric twist. The presence of a combined horizontal joint of the “cardan” type and a swing compensator at the tail rotor hub makes it possible to ensure a more even redistribution of the lifting force over the surface swept by the propeller in flight.

The helicopter fuselage is aerodynamically asymmetrical. This can be seen from the curves of the fuselage lift coefficient C 9f and drag coefficient C depending on the angles of attack a f (Fig. 1.4). The lift coefficient of the fuselage is equal to zero at an angle of attack slightly greater than 1, therefore, the lift will be positive at angles of attack greater than Г, and negative at angles of attack less than 1. The minimum value of the fuselage drag coefficient C will be at an angle of attack equal to zero. Due to the fact that at angles of attack greater or less than zero, the coefficient C f increases, it is advantageous to fly at angles of attack of the fuselage close to zero. For this purpose, the angle of inclination of the main rotor shaft forward is 4.5 °.

The fuselage without a stabilizer is statically unstable, since an increase in the angles of attack of the fuselage leads to an increase in the longitudinal moment coefficient, and, consequently, the longitudinal moment acting on the pitch-up and tending to further increase the angle of attack of the fuselage. The presence of a stabilizer on the tail boom of the fuselage ensures longitudinal stability of the latter only at small installation angles from +5 to -5° and in the range of small angles of attack of the fuselage from -15 to + 10°. At high stabilizer angles and high angles of attack of the fuselage, which corresponds to flying in autorotation mode, the fuselage is statically unstable. This is due to the flow stall from the stabilizer. Due to the helicopter's good controllability and sufficient control margins in all flight modes, it uses a stabilizer that is not controlled in flight with a setting angle of -6°.

Rice. 1.4. Dependence of the fuselage lift coefficient Suf and frontal resistance Cxf of the fuselage on the angles of attack a° of the fuselage

In the transverse direction, the fuselage is stable only at large negative angles of attack -20° in the range of slip angles from -2 to + 6°. This is due to the fact that an increase in slip angles leads to an increase in the coefficient of the roll moment, and hence the transverse moment, which tends to further increase the slip angle.

In terms of travel, the fuselage is unstable at almost all angles of attack at low slip angles from -10 to +10°, at angles greater than those indicated, the stability characteristics are improved. With sliding angles of 10°< b < - 10° фюзеляж нейтрален, а при скольжении больше 20° он приобретает путевую устойчивость.

If we consider the helicopter as a whole, then although it has sufficient dynamic stability, it does not cause great difficulties when piloting even without an autopilot. The Mi-8 helicopter was generally rated with satisfactory stability characteristics, and with the automatic stabilization systems turned on, these characteristics improved significantly, the helicopter was given dynamic stability in all axes, and therefore piloting is greatly facilitated.

4. LAYOUT OF THE HELICOPTER

The Mi-8 helicopter (Fig. 1.5) consists of the following main parts and systems: fuselage, take-off and landing devices, power plant, transmission, main and tail rotors, helicopter control, hydraulic system, aviation and radio-electronic equipment, cabin heating and ventilation systems , air conditioning systems, air and anti-icing systems, devices for external suspension of goods, rigging and mooring and household equipment. The helicopter fuselage includes nose 2 and central 23 parts, tail 10 and end 12 beams. In the bow, which is the cockpit, there are pilot seats, instrument panels, electric consoles, an AP-34B autopilot, and command control levers. Cockpit glazing provides good visibility; right 3 and left 24 blisters are equipped with emergency release mechanisms.

In the forward part of the fuselage there are niches for installing containers with batteries, plug-in connectors for airfield power, tubes for air pressure receivers, two taxiing and landing lights and a hatch with a cover 4 for access to the power plant. The forward part of the fuselage is separated from the central part by a docking frame No. 5H, in the wall of which there is a doorway. A flight engineer's folding seat is installed in the doorway. In front, on the wall of frame No. 5H, there are shelves of radio and electrical equipment, in the back - containers of two batteries, a box and an electric winch control panel.

In the central part of the fuselage there is a cargo compartment, to enter which there is a sliding door 22 on the left, equipped with an emergency reset mechanism. At the upper front corner of the sliding door opening, a side boom is attached from the outside. In the cargo compartment, folding seats are installed along the right and left sides. Mooring units and an electric winch are located on the floor of the cargo compartment. Above the cargo compartment there are engines, a fan, a main gearbox with a swashplate and a main rotor, a hydraulic panel and a consumable fuel tank.

Shock absorbers and struts of the main 6, 20 and front / landing gear, external fuel tanks 7, 21 are attached to the fuselage nodes from the outside. A kerosene heater is located in front of the right external fuel tank.

The cargo compartment ends with a rear compartment with cargo flaps. In the upper part of the rear compartment there is a radio compartment, in which panels for radio and electrical equipment are installed. There is a hatch for entering the radio compartment and the tail boom from the cargo compartment. Cargo flaps close the opening in the cargo compartment, designed for rolling in and out of wheeled vehicles, loading and unloading bulky cargo.

In the passenger version, 28 passenger seats are attached to special profiles located along the floor of the central part of the fuselage. On the starboard side in the rear of the cabin is a wardrobe. The right side panel has six rectangular windows, the left - five. The rear side windows are built into the emergency hatch covers. The cargo flaps in the passenger version are shortened, on the inside of the left flap there is a luggage compartment, and in the right flap there are boxes for containers with batteries. An opening was made in the cargo doors for the rear entrance door, consisting of a leaf and a ladder.

Rice. 1.5 Helicopter layout.

1-front leg of the chassis; 2-nose fuselage; 3, 24-sliding blisters; 4-manhole cover for exit to engines; 5, 21 main chassis legs; 6-hood heater KO-50; 7, 12-outboard fuel tanks; 8-hoods; 9-reduced frame; 10-central part of the fuselage; 11-hatch cover in the right cargo door; 12, 19 cargo doors; 13 tail boom; 14 stabilizer; 15-end beam; 16 fairing; 17-tail support; 18 ladders; 20-sash shield; 23-sliding door; 25-emergency hatch-window.

A tail boom is docked to the central part of the fuselage, to the nodes of which the tail support and an uncontrolled stabilizer are attached. The tail shaft of the transmission passes inside the tail boom in its upper part. An end beam is attached to the tail boom, inside which an intermediate gearbox is installed and the end part of the transmission tail shaft passes. From above, a tail gearbox is attached to the end beam, on the shaft of which a tail rotor is installed.

The helicopter has a non-retractable tricycle landing gear. Each landing gear is equipped with liquid-gas shock absorbers. The wheels of the front strut are self-orienting, the wheels of the main struts are equipped with shoe brakes, to control which the helicopter is equipped with an air system.

The power plant includes two TV2-117A engines and systems that ensure their operation.

To transfer power from the engines to the main and tail rotors, as well as to drive a number of units, a transmission is used, consisting of the main, intermediate and tail gears, tail shaft, fan drive shaft and main rotor brake. Each engine and main gearbox has its own autonomous oil system, made according to a direct single-circuit closed circuit with forced oil circulation. To cool the oil coolers of the engines and the main gearbox, starter-generators, alternators, air compressor and hydraulic pumps, the helicopter is provided with a cooling system consisting of a high-pressure fan and air ducts.

Engines, main gearbox, fan and panel with hydraulic units are covered with a hood. When the hood covers are open, free access to the units of the power plant, transmission and hydraulic system is provided, while the open engine hood covers and the main gearbox are working platforms for performing maintenance of the helicopter systems.

The helicopter is equipped with passive and active fire protection equipment. Longitudinal and transverse fire partitions divide the engine compartment into three compartments: the left engine, the right engine, the main gearbox. The active fire-fighting system provides the supply of fire-extinguishing composition from four cylinders to the burning compartment.

The main rotor of the helicopter consists of a sleeve and five blades. The sleeve has horizontal, vertical and axial hinges and is equipped with hydraulic dampers and centrifugal blade overhang limiters. The blades of all-metal construction have a visual spar damage alarm system and an electrothermal anti-icing device.

The tail propeller is pushing, pitch variable in flight. It consists of a cardan-type bushing and three all-metal blades equipped with an electrothermal anti-icing device.

Dual helicopter control consists of longitudinal-transverse control, directional control, combined control "Step - gas" and control of the main rotor brake. In addition, there is a separate control of the power of the engines and their stop. The change in the common pitch of the main rotor and the longitudinal-transverse control of the helicopter are carried out using the swashplate.

To ensure control of the helicopter, hydraulic boosters are included in the system of longitudinal, transverse, directional control and collective pitch control according to an irreversible scheme, for supplying which the main and backup hydraulic systems are provided on the helicopter.

The AP-34B four-channel autopilot installed on the Mi-8 helicopter ensures the stabilization of the helicopter in flight in roll, heading, pitch and altitude.

To maintain normal temperature conditions in the cabins and clean air, the helicopter is equipped with a heating and ventilation system that supplies heated or cold air to the crew and passenger cabins. When the helicopter is operated in areas with a hot climate, two on-board freon air conditioners can be installed instead of a kerosene heater.

The anti-icing system of the helicopter protects the main and tail rotor blades, two front windows of the cockpit and engine air intakes from icing.

Anti-icing device for propeller blades and cockpit glass - electrothermal, and engine air intakes - air-thermal action.

The aviation and electronic equipment installed on the helicopter ensures the performance of flights day and night in simple and difficult meteorological conditions.

A number of original technical solutions were used in the design of the helicopter: large-sized duralumin forgings, glue-welded joints, and an automatic engine control system. Compared to the Mi-4, the new helicopter had higher flight characteristics and twice the payload. The first experimental B-8 with one AI-24V engine and a four-bladed propeller from the Mi-4 first took to the air on June 24, 1961 (test pilot B.V. Zemskov). On August 2, 1962, test pilot N.V. Lyoshin took off the V-8A prototype with two TV2-117 and a five-bladed propeller from the ground, and on September 17, his first free flight took place.

In May 1964, the assembly of the new passenger V-8AP in the version of the government cabin was completed. It almost did not differ from the V-8AT and served as the basis for testing the modernized AP-34B autopilot and main rotor speed synchronizer. V-8AP was shown to the leaders of the party and government. In September of the same year, the second stage ("B") of the joint state tests program began with flights to the V-8AP. Having successfully completed the state testing program, the V-8AP was converted in the spring of 1965 at the pilot plant of plant No. 329 into a comfortable version for transporting 28 passengers. By this time, the experimental V-8AP helicopter had been practically brought to perfection, the resource of most of its units reached 500 hours. recognized as one of the most successful medium-class helicopters. The helicopter was demonstrated just as successfully a few months later at an industrial exhibition in Copenhagen. In the future, Mi-8 helicopters almost every year took part in all major international air shows and exhibitions, adequately representing the domestic aviation industry in different parts of the globe.

Serial production of the Mi-8 began in March 1965 at aircraft factory No. 387 in Kazan. Already at the end of the year, the first serial samples left the assembly shop. By 1969, the Mi-8 had completely replaced the Mi-4 on the assembly line. In 1970, the Ulan-Uden plant also started its production.

Mi-8 helicopter of a single-rotor scheme with a five-bladed three-hinged main rotor and a three-bladed tail rotor. The undercarriage is tricycle, non-retractable, with a self-orienting front leg fixed in flight. There is a tail support to protect the tail rotor. The Mi-8P helicopter differs from the transport Mi-8T in its rectangular windows and the absence of a Doppler ground speed and drift angle DIV-1 antenna on the tail boom. In the cabin of the main version of the Mi-8P, 28 soft passenger seats are installed. The twenty-eight-seat layout of the passenger compartment became the main one on the serial Mi-8P. Only in 1968 did it undergo a slight revision. The rear fuselage compartment was changed - a luggage compartment was located in it. The passenger cabin has lengthened by more than a meter. The rear doors were made smaller, and a rear entrance door with a ladder was installed in them. The Mi-8P could also be used as an ambulance or transport helicopter for transporting small-sized cargo inside the cabin and large-sized cargo on an external sling. A few years later, on the basis of the Mi-8P and its later modifications, variants with a passenger cabin for 20, 24 and 26 seats were created. The Mi-8P can be used as an ambulance and transport (small cargoes inside the cabin, large cargoes on an external sling).

In 1968, the rear fuselage design was revised. There was a luggage compartment. The passenger compartment has lengthened by more than a meter. The rear doors became smaller, they installed a rear entrance door with a ladder.

In 1962-1991, about 5,200 Mi-8 helicopters were manufactured at two factories (3,700 in Ulan-Ude). Of these, about 2800 were exported to 40 countries of the world. Half of the helicopters produced are still in operation. In 1964-1967, 7 international records were set on the Mi-8 (most by female crews).

Modifications:

B-8A - the second prototype. It featured two engines and a five-bladed propeller.
V-8AP - the fourth prototype. Made in 1964 in the version of the government salon. In 1965 it was converted into a passenger version.
Mi-8APS, Mi-8AP-2, Mi-8AP-4 - enhanced comfort options ("salon"). They differ in engine. TV2-117AG. Produced in Ulan-Ude.
Mi-8M - upgraded for 40 passenger seats (project). It featured a lengthened fuselage and TV3-117 engines. Developed in 1964-1971.
Mi-8PA - with boosted TV2-117F engines (1700 hp). Certified in Japan in 1980.
Mi-8PS - salon "for 7, 9 or 11 passengers (respectively Mi-8PS-7, Mi-8PS-9, Mi-8PS-11).
Mi-8S - (the second with this designation) - "salon" based on the Mi-8T. Designed in 1969.

Modification: Mi-8P
Main propeller diameter, m: 21.29
Tail rotor diameter, m: 3.91
Length, m: 18.17
Height, m: 5.65
Weight, kg
- empty: 6800
- normal takeoff: 11100
-maximum takeoff: 12000
Engine type: 2 x GTD TV2-117A
- power, kW: 2 x 1257
Maximum speed, km/h: 250
Cruise speed, km/h: 225
Practical range, km: 480
Practical ceiling, m: 4500
Static ceiling, m: 1900
Crew, people: 2-3
Payload: up to 28 passengers or 12 stretchers with attendants or 4000 kg of cargo in the cabin or 3000 kg on the suspension.

An experienced B-8A helicopter is the second prototype.

The third B-8A prototype in flight.

An experienced V-8AP helicopter is the fourth prototype. 1964

An experienced V-8AP helicopter is the fourth prototype. 1964

Experienced helicopter V-8AP.

Mi-8P of the first series in flight.

Helicopter Mi-8P. Mi-8T in the background.

Mi-8P landing on the platform near the Peter and Paul Fortress. St. Petersburg.

Mi-8P helicopter at the site near the Peter and Paul Fortress.

Mi-8P "Altai Airlines".

Mi-8P company "Yu Tair" in the parking lot.

Mi-8P comes in for landing.

Government Mi-8PS.

Government Mi-8PS.

Cabin Mi-8P.

Mi-8 is a multipurpose and widely used helicopter. Designed and developed by the designers of OKB M.L. Mile in the early 60s. This Soviet development is the most massive twin-engine air transport vehicle in the world (it is on the list of the most common helicopters in world aviation history). It has two directions: military and civil.

In July 1961, the B-8 prototype flew for the first time. A year later, the second copy of the B-8A was released. In 1967, the Mi-8, which had already been completely modified and changed its old name to the new one, entered service with the Air Force of the Soviet Union. Since the model proved to be one of the most successful, the current Russian Air Force is also ordering this helicopter. At the moment, this unit is used in fifty countries around the world.

The key modification of the 80s was the developed Mi-8MT. The improved version, or, as it is also called, “product 88”, differs from its counterpart in improved power mechanization (two TVZ-117 engines) and an installed auxiliary power-type structure. True, this option is not so common around the world.

In 1991, the development of a new civil air transport helicopter Mi-8AMT began. In the late 90s, the Mi-8AMTSh water transport assault helicopter was developed. In total, over 3500 copies were produced.

Mi-8 design

The Mi-8 is a single-rotor helicopter with five rotors and three tail rotors. The rotors are fixed by vertical, horizontal and axial hinges, and the steering blades, respectively, are of a combined cardan type. The transmission is exactly the same as that of the Mi-4. All-metal propeller blades include a hollow spar pressed from an aluminum alloy. Attached to its rear stern are 24 aluminum foil honeycomb compartments (profiling). The rotor blades are equipped with an alarm for possible damage to the spar.

An advanced antifreeze system prevents the helicopter from icing up. It is electrified and has the ability to work both in autonomous and manual modes (feeding 208 volts). In the event that there was a failure of one of the engines, respectively, the other automatically increases its power. And it does not affect level flight and altitude. Three KAU-30B hydraulic boosters contribute to the high-quality control of the main rotor, and RA-60B steering boosters.

The tricycle landing gear is not retractable. The tail support prevents the tail rotor from touching the ground. Thanks to the external suspension system, the helicopter can carry cargo weighing up to three thousand kilograms. Roll, direction, pitch and flight altitude stabilization is provided by the AP-34 four-channel autopilot.

The passenger modification can accommodate up to 18 seats, and the transport modification can accommodate 24 seats. The internal climate, heat and cold support are controlled by KO-50 (kerosene heater) and a specially designed ventilation system. Thanks to navigation instruments and radio equipment, the Mi-8 can fly, regardless of weather conditions and time of day.

Depending on the application, there is a huge difference between the modifications. One of the first Mi-8s took off into the air thanks to two TV2-117 engines. Their power was 1500 hp, and the 10-stage compressor was started from the starter-generator GS-18TO. The start of the starter-generator of the first engine is powered by six 12CAM28 batteries with a voltage of 24 V, and the second is powered by the starter-generator of an already running engine.

During the operation of the GS-18TO engines, a voltage of 27 V is supplied to the main power supply system. Two batteries are installed in the cargo compartment, and the remaining four are mounted in the pilot's cabin. Although their capacity is small, it still does not interfere with powering five engine starts in turn. They provide current in excess of 600-800 amperes, while being charged from generators (direct current) and can automatically turn on and off. This ability is made possible by differential-minimum relays (generator control).

The PT-500Ts converter feeds gyroscopic devices with a three-phase voltage of 36 volts. The SGO-30U generator supplies a single-phase current (208 V) to the heating elements of windshields and propellers. Two single-phase transformers TS/1-2 and Tr-115/36 depart from SGO-30U. The first feeds the navigation equipment, and the second feeds the transmission and engine control devices. In the event of malfunctions and failure of the SGO-30U operation, all equipment in an autonomous mode goes to the PO-750A converter.

Later series Mi-8MT, Mi-17 and others differ significantly from the base model. The installed TV3-117 engines are much more powerful. The air supply to the starters is carried out by the APU AI-9V and the starter generator STG-3. The power supply system produces a voltage of 208 V with a frequency of 400 Hz. It is powered by SGS-40PU generators, which are located on the main gearbox. To start the APU and, if necessary, emergency power, batteries 12CAM-28 are installed.

The main power supply is carried out by three VU-6A rectifiers. The first generator is responsible for supplying current to VU No. 1, heating elements of the transformer and screws, and the second feeds VU No. 2 and No. 3, the glass heating mechanism and the engine ROM. In some modifications, the TC/1-2 transformer is additionally heated.

If one generator fails, TS310S04B switches to the second one; if both fail, then the PT-200Ts and PO-500A converters are launched.

The helicopter has two hydraulic systems: main and backup. The pump NSh-39M, installed on the main gearbox, creates pressure in each of them. Its adjustment takes place with special automatic machines GA-77V. Support in the main system is carried out by two hydraulic accumulators, in the backup system - by one. Separate electromagnetic cranes GA192 include hydraulic power supply RA-60B, KAU-30B of the common main rotor and two KAU-30B control of flow and transverse types.

There are many types of Mi-8 upgrades. They are divided into types:

1. Experienced

V-8 - the first experimental helicopter with one installed AI-24V gas turbine engine;

B-8A - the second copy with the presence of two gas turbine engines TV2-117;

V-8AT - the third created prototype;

V-8AP is the fourth and last prototype.

2. Passenger

Mi-8P - passenger-type helicopter with 28 seats;

Mi-8PA - modification with GTD TV2-117F engines;

3. Transport workers

Mi-8T - transport and landing helicopter;

Mi-8TS is an export model for the Syrian Air Force. A dry climate has been taken into account.

4. Multipurpose

Mi-8TV - adopted by the USSR in 1968. The modification includes booking of the cockpit, engines and gearbox hoods, as well as the presence of four Malyutka ATGMs and an A-12.7 machine gun;

Mi-8AT - TV2-117AG engines;

Mi-8AV - used to lay mines (up to 200 pieces) against ground forces;

Mi-8AD - designed to install small-sized anti-personnel mines;

Mi-8MT - TV3-117 engines;

Mi-8MTV - TV3-117VM engines;

• Mi-8MTV-5 - modified nose of the helicopter;

  Mi-8MTKO - installation of lighting equipment and night vision devices;

• Mi-171 - issued a certificate of the International Aviation Committee. Its modifications are Mi-171A1 and Mi-17KF.

There were also Mi-8TG, Mi-14, Mi-18, Mi-8MSB. For special cases, a number of special-purpose helicopters have been developed. Some of them should be noted. For example, the Mi-8TECh-24 was used for maintenance and repair work. On board there was a plumbing and control equipment. Mi-8SPA was engaged in search and rescue operations. Mi-8K - artillery air spotter. The same Mi-8VKP directly represented the command post of the air plan. The air hospital was represented by a Mi-8MB helicopter.

It was especially different from all Mi-8AMTSh. Helicopter transport-assault type is widely used by many countries. Equipped with a weapon system and reinforced cockpit and engine armor.

Helicopter development.

In 1960, OKB Mil M.L. began the development of a new transport helicopter that would replace the obsolete Mi-4. An experimental prototype with the designation V-8 made its first flight in June 1961. The helicopter was equipped with one AI-24 gas turbine engine and a four-bladed main rotor from the Mi-4. Later, the designers made a number of improvements. The power plant was replaced with two TB2-117 gas turbine engines. The main rotor became five-bladed.

Engine AI-24.

Production and release.

Flight tests began on September 17, 1962. The helicopter fully justified the hopes placed on it. Since 1965, he went into mass production under the designation Mi-8. The design of this machine turned out to be so successful that its production and modernization are still ongoing. To date, the Mi-8 is one of the most common transport helicopters in the world. More than 8000 cars were produced in various modifications. The helicopter is operated in more than 50 countries of the world.

Mi-8 cabin

By design, the Mi-8 is a single-rotor helicopter. The semi-monocoque frame fuselage consists of the cockpit, cargo compartment and tail boom. The cockpit is triple designed for two pilots and a flight mechanic. The cargo cabin can be adapted for the carriage of goods or equipped with seats for passengers. In the transport version, loading is carried out through a double-leaf cargo hatch. Chassis tricycle non-retractable. The power plant consists of two gas turbine engines TV2-117A (TV3-117MT), 2x1710 (2x3065) hp. Five-bladed main rotor with all-metal blades. The tail screw is three-bladed.

Engine TV2-117A.

Helicopter mods.

There are more than 30 modifications of this machine, the main ones being Mi-8T (transport) and Mi-8P (passenger). The Mi-8AMTSh is an air assault variant with rocket and machine gun armament. The helicopter is used to perform a wide range of tasks, both in civil aviation and in the Air Force. Since the 70s, the Mi-8 has been used in many military conflicts in different parts of the world.

Mi-8P (passenger).

Mi-8T (transport).

The main characteristics of the Mi-8

The maximum takeoff weight of the helicopter is 12000 (13000) kg. Maximum speed 250 km/h. Practical ceiling 4500 m. Practical range 480 km. The load can consist of 4000 kg in the cargo compartment or 3000 kg on the external sling. The passenger version is designed to carry 24 passengers. In various amphibious transport modifications, the helicopter can accommodate about 30 soldiers or 12 wounded on stretchers with attendants.

Exactly 50 years ago, on August 2, 1962, the first prototype of the Mi-8 multi-purpose helicopter took off for the first time. Mi-8 (according to the NATO classification Hip) is a Soviet and Russian multi-purpose helicopter created by the Design Bureau of M. L. Mil in the early 60s of the last century. Currently, it is the most massive twin-engine helicopter in the world, and is also one of the most popular helicopters in aviation. Widely used to solve a large number of civil and military tasks. The helicopter has been in service with the Soviet Air Force since 1967 and proved to be such a successful type of equipment that its purchases for the Russian Air Force continue to this day. At the same time, the Mi-8 helicopter is operated in more than 50 countries of the world, including such states as China, India and Iran.

Over its half-century history of serial production and design work to improve this helicopter, Soviet and Russian designers have created about 130 different modifications, more than 13,000 machines of this type have been produced. Today these are Mi-8MTV-1, MTV-2, MTV-5, Mi-8AMTSh, Mi-171, Mi-172 helicopters. In 2012, the Mi-8 is not just a hero of the day - it is a first-class multifunctional helicopter, which today is one of the most successful products of the domestic helicopter industry. Even after 50 years, the car is in demand all over the world and is purchased even by NATO member states. From 2006 to 2008, 26 Mi-171Sh military transport helicopters were delivered to the Czech Republic and Croatia.

To date, the plants for the production of Mi-8/17 Ulan-Ude Aviation Plant JSC and Kazan Helicopter Plant JSC, which are part of the Russian Helicopters holding, are operating stably and are loaded with orders for the production of these helicopters for 2 years in advance. At the same time, work on the modernization of this machine is continuously ongoing. OAO Moscow Helicopter Plant named after M.L. Mile is currently assembling the first prototype of the upgraded version of the Mi-171A2 helicopter, and the technical design of this helicopter has also been determined. The helicopter was created on the basis of the Mi-171 helicopter and should become a worthy development option for the entire family of Mi-8 helicopters.

Mi-8P passenger

Throughout its history, Mi-8 family helicopters have taken part in a large number of local conflicts, they have saved thousands of lives, withstood severe Siberian frosts, catastrophic heat and sudden temperature changes, desert dust and tropical downpours. 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. Created in the middle of the last century, the Mi-8 multi-purpose helicopter is still one of the most in demand in its class today and will be in demand on the Russian and world aviation markets for many years to come. Over the long years of production, the Mi-8 has become the basis for many unique developments, for example, the Mi-14 "amphibious helicopter".

The design of the Mi-8 helicopter

The Mi-8 helicopter was made according to a single-rotor scheme with a tail rotor, tricycle landing gear and two gas turbine engines. The fuselage of the machine has a frame structure and consists of the nose, central, tail and end beams. In the nose of the helicopter there is a cockpit for three people: two pilots and a flight engineer. The cockpit glazing provides the helicopter crew with a good overview, the right and left blisters are movable and equipped with emergency drop mechanisms.

In the passenger version of the helicopter, the cabin had dimensions of 6.36 x 2.05 x 1.7 meters and was equipped with 28 seats, which were placed in 2 rows on each side with a step of 0.74 m and a passage of 0.3 m. sashes, an opening was made under the back entrance door, which consisted of a ladder and sashes.

The tail boom of the helicopter had a riveted design of a beam-stringer type and was equipped with a working skin. It was equipped with nodes for attaching the tail support and a controlled stabilizer. The helicopter was equipped with a stabilizer with a size of 2.7 m and an area of ​​2 m2 with a NACA 0012 profile; its design was single-spar.

The landing gear of the helicopter was tricycle, non-retractable. The front landing gear was self-orienting and consisted of 2 wheels measuring 535 x 185 mm. The main bearings of the uniform type helicopter were equipped with liquid-gas two-chamber shock absorbers and wheels measuring 865 x 280 mm. The helicopter also had a tailwheel, which served to prevent the tail rotor from touching the ground. The support consisted of a shock absorber, 2 struts and a support heel. The chassis track was 4.5 meters, the chassis base was 4.26 meters.

Mi-8T Serbian Air Force

The fuel system included a fuel tank with a capacity of 445 liters, a right hanging tank with a capacity of 680 or 1030 liters, a left hanging tank with a capacity of 745 or 1140 liters, and an additional tank in the cargo compartment with a capacity of 915 liters. The transmission of the helicopter consisted of 3 gearboxes: main, intermediate and tail, main rotor and brake shafts. The main gearbox of the helicopter transfers power from the engines, which have an output shaft speed of 12,000 rpm, to the main rotor at a speed of 192 rpm, as well as the tail rotor at a speed of 1,124 rpm and the fan - 6,021 rpm /min, which serves to cool the main gearbox and engine oil coolers. The total weight of the helicopter oil system is 60 kg.

The control of the helicopter was duplicated, with cable and hard wiring, as well as hydraulic boosters, which were driven from the backup and main hydraulic systems. The existing four-channel autopilot AP-34B provided the helicopter with stabilization in flight in heading, roll, altitude and pitch. The main hydraulic system of the helicopter ensured the operation of all hydraulic units, the pressure in the system was 4.5 MPa, the backup system provided only the operation of hydraulic boosters, the pressure in it was 6.5 MPa.

Mi-8AMTSh

Currently, the Russian Armed Forces continue to purchase Mi-8 helicopters. As part of the state defense order, until 2020, Mi-8AMTSh vehicles should be delivered to the troops. Mi-8AMTSh is an attack military transport helicopter (export designation Mi-171Sh). The helicopter is designed to fight against armored ground, surface, mobile and stationary small targets, to destroy enemy manpower, transport troops, cargo, wounded, as well as perform search and rescue operations. The helicopter was developed at the Ulan-Ude Aviation Plant in close cooperation with JSC MVZ im. M.L. Mile.

To solve combat missions, the helicopter can be equipped with a missile and small arms and cannon armament system, as well as a set of means of protection against damage, sanitary and airborne transport equipment, as well as instrumentation and electronic equipment, which allows the helicopter to fly at any time of the day, including and in difficult weather conditions. At the same time, the conversion of the Mi-8AMTSh helicopter from a combat version to an ambulance or airborne transport version does not require much time and can be carried out directly during the preparation for the flight to perform the corresponding task.

Mi-8AMTSh (export version of Mi-171Sh)

The crew of the car includes:

- commander - left pilot, piloting a helicopter, aiming and using unguided weapons, when launching guided missiles, he performs the "shooting" mode.
- the second pilot, is engaged in piloting a helicopter to help the crew commander; performs the functions of the operator of the Shturm-V complex when searching for targets, launching and aiming guided missiles at the target, and also performs the duties of a navigator.
- a flight mechanic, in addition to performing his regular functions, also performs the functions of a gunner for the stern and bow machine gun installations.

The main distinguishing feature of the Mi-8AMTSh helicopters was the inclusion of modern Shturm-V ATGMs and Igla-V air-to-air missiles into their armament. The complex of high-precision guided missiles "Shturm" allows you to quite effectively hit armored vehicles, including those equipped with dynamic protection, low-speed air targets, manpower and enemy fortified points. In terms of the range of possible weapons, the MI-8AMTSh came close to the Mi-24 attack helicopter, while having a greater variability of use.

Sources of information:
- http://www.vertolet-media.ru/helicopters/mvz/mi-8amtsh/
- http://www.armstrade.org/includes/periodics/news/2012/0731/150014112/detail.shtml
- http://www.aviastar.org/helicopters_rus/mi-8-r.html
- http://ru.wikipedia.org/wiki/%D0%9C%D0%B8-8