Helicopter V-12 is the most severe and lifting helicopter in the world. It was created in 1967 to cost centers under the leadership of Mil.
In 1969, it set a world record for carrying capacity - 40 tons. A distinctive feature is the lateral position of the screws on the reverse delta wings, which are driven by four engines D-25VF. B-12 was designed as a super-heavy transport helicopter with a carrying capacity of not less than 30 tons, to transport components of intercontinental ballistic missiles for parts of the Strategic Missile Forces, the creation of positional areas for which it was planned in areas without paved roads.
In the early 50s there is a need in the heavyweight destantno transport helicopters capable of transporting military equipment weighing up to 6 tons: artillery with tractors, trucks and airborne self-propelled. That was the helicopter Mi-6, with a five-blade main rotor with a diameter of over 30 m and engines D-25B created on EDO Soloviev PA. Air giant Mi-6 marked the beginning of a new direction in the development of world helicopter - the creation of heavy-lift helicopters. In 1961 Dementiev formally approved the assignment to elaborate helicopter lifting capacity 20-25t. May 3, 1962 was followed by a decree of the Council of Ministers of the USSR on the development of the B-12 cargo cabin similar to the cockpit of a giant Antonov An-22.
To reduce the cost of development, and to accelerate the construction and deployment of the helicopter designers decided to create it by doubling the propeller group of Mi-6 (rotor, power unit, main gearbox and control system), a tested and is in mass production and wide use. The project was a giant air chetyrёhdvigatelny unit for twin screw transverse scheme.
At the ends of each truss console-wing propeller-nacelle was with two turbine engines D-25VF capacity of 6500 hp each. The wing had a slight narrowing of the reverse cross V. Inside it passes the transmission shaft, the timing turns both screws. Fuel was in the wing and external fuel tanks suspended.
4. rotors (picture missing) five lobes, have the same design as the Mi-6 and are arranged with a minimum overlap of ~ 3 m, all-metal blade of the MI-6 have been replaced with new blades composite construction with a steel spar, fiberglass nose section and sections of the back of a foiled honeycomb.
5. Cabin crew storey, at the bottom of the cabin placed two pilots, a flight engineer and bortelektrik at the top - a navigator and radio operator. Wing verhneraspolozhennoe, scale 28, 4 m, different reverse delta (end chord root twice) and large cross V (-), is supported by a truss struts connected to the fuselage and landing gear.