Trực thăng-Phần 2

B 47J - Sycamore

AS 335N - Explore

S 269 - Seasprite

Twinstar - Widgeon

Mil Mi-1
1948

Mikhail Mil, who must rank with Igor Sikorsky as one of the world''s leading exponents of rotorcraft design, was a contemporary of Nikolai Kamov at the TsAGI (Central Aero and Hydrodynamic Institute) during the 1930s. Given charge of his own design bureau in 1947, he became responsible for the first Soviet helicopter to go into quantity production. Originally designated GM-1, the Mi-1 prototype was completed and flown in September 1948 and was a compact machine with a fully-enclosed metal-skinned fuselage. It was built to a single main rotor configuration, with a small anti-torque rotor at the rear - a layout to which Mil, like Sikorsky, has adhered firmly ever since. The Mi-1 made its public debut at the Tushino Air Display in 1951, by which time it was already in production and service with the Soviet armed forces.
Subsequent production of the Mi-1, both in the Soviet Union and in Poland, has been extensive. In ad***ion to those built for the Soviet armed forces, military Mi-1''s have also been supplied to the DOSAAF and the air forces of Albania, Afghanistan, Cuba, Czechoslovakia, Finland, Iraq, Poland, Syria, the United Arab Republic and the Yemen. A wide range of duties has included those of observation, liaison, rescue, ambulance and training. Wide use was also made of the Mi-1 by Aeroflot and by civil authorities in the Soviet Union and other Soviet bloc countries. The standard Mi-1 seats 3 passengers in ad***ion to the pilot; variants include the Mi-1T, which carries only 2 passengers, the Mi-1U which is a dual-control trainer and the Mi-1NKh, a utility model for such duties as freight and mail carriage, ambulance and agricultural operations. Other models to appear were the 1956 Mi-3, a slightly heavier version with a 4-blade main rotor, wider cabin and ad***ional flight aids; and the Mi-1 Moskvich, a refined version of the standard Mi-1 produced for Aeroflot.
Polish production began with the standard Mi-1 late in 1955, this being built at the WSK works at Swidnik under the designation SM-1 with a licence-built version of the AI-26V engine. Several of the Mi-1''s supplied to foreign air forces were Polish-built, and subsequent versions included the SM-1W (pilot and 3 passengers), SM-1WS (2-stretcher ambulance), SM-1WZ (agricultural) and SM-1WSZ (dual-control trainer). Production of the Mi-1/SM-1 is thought to have been phased out around 1963 in favour of the later turbine-powered developments, but large numbers of these useful little machines are still active in many parts of the world.

Technical data for Mi-1
Crew: 1, passengers: 2, engine: 1 x Rybinsk AI-26V pistone engine, rated at 432kW, main rotor diameter: 14.35m, length without rotors: 12.05m, height: 3.28m, take-off weight: 2550kg, empty weight: 1900kg, max speed: 190km/h, cruising speed: 140km/h, service ceiling: 4000m, hovering ceiling: 2000m, range: 360km, payload: 500kg

Mil Mi-4
1952

Design work on the Mi-4 helicopter started in the second half of 1951 and the aircraft was flown in prototype form in August 1952. In appearance it closely resembled the contemporary Sikorsky S-55, but in terms of size and performance it equated with Sikorsky''s later S-58. The Mi-4 was already in Soviet Air Force service by August 1953, when it was first seen publicly at the Tushino Aviation Day display, and it has since become the most widely built of all Soviet helicopters. Production is believed to have ceased around 1964, by which time several thousand had been built both in the Soviet Union and in China.
The Mi-4 was produced initially as a troop and assault transport helicopter for the Soviet armed forces. This version is characterised by circular cabin windows and a ventral fairing in which an observer can be stationed if required. Alternatively an ad***ional fuel tank can be fitted in this position. One major difference between the Mi-4 and the S-55 is that the former has clamshell rear loading doors through which a maximum internal payload of 1600kg can be admitted. Typical military loads of the Mi-4 include 14 fully equipped troops, a GAZ-59 command vehicle, a 76mm anti-tank gun or 2 motorcycle combinations. Military Mi-4''s have been exported to a number of air forces in the Soviet bloc, among the largest users being India, which has sixty, and Cuba, which has twenty-four.
From 1964 two civil versions of the Mi-4 were also built in considerable numbers. These were the Mi-4P (Passajirskii == passenger) and the Mi-4S (Selskokhoziaistvennii = rural economy). The Mi-4P is the standard version for Aeroflot, carrying 11 passengers normally or up to 16 in high density seating or, in the ambulance role, 8 stretchers and a medical attendant. The Mi-4P is distinguished by having square cabin windows, wheel spats and no ventral fairing; 100kg of baggage can be carried in ad***ion to the normal passenger complement. The Mi-4S is normally used for agricultural operations, when it can be fitted with a 1000kg dust hopper or a 1600-l tank holding pesticide or fire-fighting chemical. All versions of the Mi-4 have provision for fitting inflatable pontoons in ad***ion to the wheeled landing gear. A stripped-down Mi-4 established a number of speed-with-payload and payload-to-altitude records in 1956, and in more recent years both military and civil Mi-4''s have performed a considerable amount of useful work in the Polar regions, their tasks including ice patrol and geological survey.

Design of the Mil Mi-4, a conventional helicopter with about four times the capacity of the Mi-1, was initiated in 1951 and the first example was flown during May 1952. Produced initially for use by the Soviet armed forces in assault and troop transport roles, the Mi-4 ''Hound-A'' has clamshell rear doors to simplify the loading of vehicles and freight; alternatively, the cabin can accommodate up to 14 troops. Military Mi-4s are recognisable easily by having a ventral gondola which was intended originally for a navigator or observer, but can also house avionics equipment. Produced in large numbers for Soviet military use, the Mi-4 was also exported for service with more than 20 foreign air arms. A number remain in current use, and in more recent years conversions have been reported in Soviet use for ASW (''Hound-B'') armed close support and ECM (''Hound-C''). From 1964 production of civil versions was initiated and combined civil/military production by Mil was estimated at 3,500 when production terminated in 1969. All versions can be equipped with inflatable pontoons which, mounted so that the landing wheels project below them, can be used for amphibious operations. The Mi-4 was also manufactured under licence in China, a total of about 1,000 built when production ended in 1979, and of which approximately two-thirds were for civil use.
Variants
Mi-4: basic military production version with clamshell rear doors; this configuration adopted also for civil cargo versions
Mi-4P: civil transport version used extensively by Aeroflot and seating eight to 11 passengers in furnished cabin; current major use in ambulance configuration carrying up to eight stretchers and a medical attendant
Mi-4S: basically an agricultural version with a large chemical container in the main cabin, but used also for fire-fighting operations Z-5: Chinese military version of the Mi-4, this being in service with both the army and navy
Xuanfeng: Chinese name for civil version of the Mi-4, at least one of which is flying with the PT6T-6 twin turbine engine

Technical data for Mi-4
Crew: 2, engine: 1 x ASh-82V pistone engine, rated at 1250kW, rotor diameter: 21.0m, length with rotors turning: 25.02m, height: 4.4m, fuselage width: 2.0m, take-off weight: 7550kg, empty weight: 5100kg, max speed: 185km/h, rate of climb: 5.6m/s, service ceiling: 5500m, hovering ceiling: 2000m, range with max fuel: 500km, payload: 1600kg