Mil W-7
| Mil W-7 | |
|---|---|
_(9734212194).jpg) Mil W-7 in Monino |
|
| Type: | Experimental helicopter |
| Design country: | |
| Manufacturer: | |
| First flight: |
February 10, 1962 |
| Commissioning: |
only prototype |
| Number of pieces: |
1 |
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The Mil W-7 ( Russian Миль В-7 ) is a Soviet experimental helicopter with a blade tip drive .
prehistory
After the end of the Second World War , the development of rotary wing aircraft in the Soviet Union, which had only been operated to a limited extent during the war years, was accelerated. Mikhail Mil opened his own OKB in 1948 and in the same year the Mi-1, the first mass-produced helicopter in the USSR, appeared. In contrast, Iwan Bratuchin's OKB was looking at alternatives to the conventional piston engine as a helicopter drive . Bratuchin had been around since the 1930s, with support - deals and helicopter structures and brought some original designs for testing, including the zweirotorigen Bratuchin Omega from 1943 that has a similar interpretation of the rotors as the later heavy transport helicopter W-12 had and the two Prototypes were tried out. In 1949 the possibility of a pulso drive was considered. An Omega helicopter was equipped with PuWRD Pulso thrust tubes developed by Vladimir Tschelomei at the rotor blade ends . The construction, now known as the M-1 , was tested until 1952 and, after evaluating the test results, it was decided to build a small, blade-tip powered helicopter.
development
The results of the testing of the M-1 were handed over to OKB Mil, which began in 1953 with the planning of a small, four-seater helicopter that was to be used as an " air taxi " and should help bridge the great distances within the Soviet Union. From a military point of view, a use as an artillery observer was obvious. A first model was inspected in March 1958 by a state commission that placed an order for five of the helicopters designated as W-7 (for Wertoljot, helicopter). For stabilization, the W-7 should be equipped with a vertical fin on the tail boom, but wind tunnel tests carried out at the ZAGI showed that this was not sufficient for this purpose. It was therefore replaced by a tail rotor that was connected to the main rotor and was driven by it, as it were. The two-bladed main rotor, in turn, received an AI-7 jet engine at each end, the fuel supply of which was ensured by containers in the blades. Construction of the prototype began in 1959. On February 10, 1962, the first test flight took place, unmanned because of the new drive system and suspended on ropes just above the ground. The rotor blades were deformed by the unbraked power delivery of the engines. The tests were therefore interrupted, the damage repaired and new MD-3 engines developed by ZIAM installed. After a three-year break, testing was finally resumed in April 1965. In the meantime, however, the use of the blade tip drive had been abandoned. The test series was therefore canceled and the project discontinued. The only W-7 built can be seen in the Museum of the Russian Air Force .
Technical specifications
| Parameter | Data |
|---|---|
| crew | 1 |
| Passengers | 3 |
| length | 6.23 m |
| height | 2.91 m |
| Rotor circle diameter | 11.60 m |
| Empty mass | 730 kg |
| Takeoff mass | normal 835 kg maximum 1,050 kg |
| drive | two AI-7 |
literature
- Nikolai Jakubowitsch: Mil W-7. Tied to the ground . In: Aviation Classics . No. 6 . Motor Presse, Stuttgart 2013, p. 46/47 .
Web links
- В-7. Retrieved June 29, 2016 (Russian).