Mi-8 Hip - Series Production
In November 1964 the joint State trials commission made the decision to recommend the helicopter for series production, and its transport and troop-carrier version for entry into service with the Armed Forces. According to the Decision of the joint State trials commission dated on November 3, 1964, Kazan Plant No. 387 was engaged for the series production of the helicopter. This enterprise was selected purposely. The Kazan Plant had already had the experience of series production of Mi-1 and Mi-4 helicopters and perfected industrial and production basis, as well as held necessary highly qualified personnel, experience of application of new vehicles.
In the winter of 1964-1965 the V-8AP was returned to Plant No. 329 and converted to a regular passenger version: it was equipped with 20 comfortable seats, a wardrobe, heat- and soundproofing, heating, ventilation and air-conditioning systems, as well as received some elements of interior design. In March of 1965 the testing of this helicopter in the GosNII GA (the State Scientific and Research Institute of Civil Aviation) was completed, and the passenger version was also recommended for series production and for entry into service with Aeroflot.
When series production was started at Kazan Plant No. 387, the new helicopter was designated Mi-8T in the transport and troop-carrier version and Mi-8P in the passenger version. The production drawings had been sent to Kazan in advance, which permitted the first production machines to leave the assembly line as early as the end of 1965. The production Mi-8T differed from the prototype in having circular side windows of the cargo hold; the rectangular windows remained a distinctive feature of the Mi-8P passenger version and its derivatives. The helicopter was manufactured with two types of external strap-on tanks: long ones, holding 1,154 and 1,044 litres and short ones, holding 680 and 745 liters, in both cases port and starboard side respectively. One or two 915-liter auxiliary tanks could be installed in the cargo cabin to extend range. In the course of joint state trials the V-8, V-8A, V-8AT and V-8AP performed a total of 140 flights, logging in all 110 hours. During the tests there was not a single flying accident worthy of note.
High professionalism of the Design Bureau staff and the personnel of the EDB's production and test facilities enabled them to turn the prototype into a reliable and advanced machine in a remarkably short time - only three years; all this was much more trouble-free than had been the case with the preceding types, including the Mi-4 which the Mi-8 was to replace.
The Mi-8 introduction into service was marked by a tragic event - in January 1966 the V-8A crashed while making a regular factory test flight, killing the entire crew which comprised N. V. Lyoshin, I. N. Dryndin and F. I. Novikov. The crash occurred after a tail rotor hub bearing disintegrated. The cause of the failure was established and rectified through appropriate improvements. In all other cases the scientific knowledge and production skills possessed by the Plant's personnel made it possible to foresee the dangers in advance and avoid them.
In the spring of 1965, after the successful completion of the State trials program, the V-8AP prototype was returned to the experimental production facility of Plant No. 329 and converted into a new passenger version providing comfortable seating for 28 persons. By then the V-8AP had been developed virtually to the degree of perfection, and the service life of most of its assemblies reached 500 hours. In June 1967 the helicopter was presented at Paris Air Show, earning high praise from foreign specialists for its excellent performance and high degree of comfort, and was recognized as being one of the most successful medium-lift helicopters. Equally successful was its demonstration at an industrial exhibition in Copenhagen a few months later. Subsequently, almost every year the Mi-8 helicopters took part in all the major international airshows and exhibitions, acting as worthy representatives of their home country's aircraft industry in different parts of the globe.
The 28-seat layout of the passenger cabin was adopted as standard on the production Mi-8P. Only in 1968 it was altered slightly. The changes concerned the aft fuselage where a baggage hold was added. The passenger cabin's length was increased by more than 1 meter (3 ft 3 in.). Airstairs were incorporated into the rear clamshell doors which were reduced in size. The Mi-8P could also be used as an ambulance or as a transport helicopter for carrying small-size cargoes inside the cabin and bulky loads externally on a sling. Several years later the Mi-8P and its later versions served as a basis for the development of passenger cabin layouts seating 20, 24 and 26 passengers.
In 1968 tests of the armed Mi-8TV version were completed. Its fuselage was flanked by outriggers with two racks on each side for the carriage of UB-16-57 rocket pods with 57-mm KARS-57 (S-5) unguided rockets, or of bombs weighing 50 to 500 kg apiece. The project originally envisaged a nose mount for a machine-gun, but it had to be dispensed with in favour of a bigger bomb load. In 1968, after the completion of firing tests, the Mi-8 light transport and troop-carrier helicopter was offcially included into the Soviet Air Force inventory. By that time the life of the major parts of the helicopter already amounted to 1000 h. Mil OKB employees S. A. Koloopayev, V. A. Kuznetsov, Ye. V. Yablonskiy, A. S. Brahverman and G. I. Remezov were awarded the prestigious State Prize of the USSR for the development of the Mi-8 multipurpose helicopter.
By 1969 the Mi-8 completely supplanted the Mi-4 on the assembly line of Plant No. 387 in Kazan. The production rate grew from year to year, eventually amounting to several hundred a year. In all, the Kazan Helicopter Plant built more than 4,500 Mi-8 helicopters in different versions powered by TV2-117 engines. The demand for the Mi-8 was so great that Ulan-Ude Aircraft Plant also switched to this helicopter in 1970. This enterprise has produced up to now more than 3,700 helicopters with TV2-117 engines.
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