Mil V-7
The Mil W-7 (Russian Миль В -7) is a Soviet experimental helicopter with blade tip drive.
Prehistory
After the end of World War II the Drehflüglerentwicklung in the Soviet Union, which had been operated only restricted during the war years, was forced. Mikhail Mil opened his own OKB 1948 and that same year appeared with the Mi- 1, the first mass-produced helicopter in the USSR. In OKB of Ivan Bratuchin you dealt with, however, alternatives to conventional piston engine as a helicopter engine. Bratuchin had been dealing since the 1930s with the support and helicopter designs and brought some original designs for testing, including the zweirotorigen Bratuchin Omega from 1943, which had a similar interpretation of the rotors as the later -lift helicopters to W-12 and the two prototypes were tested. In 1949 the possibility of a Pulsoantriebs was envisaged. An omega- helicopter was thus equipped to the rotor blade tips with PuWRD - Pulso jet pipes that had been developed by Vladimir Tschelomei. By 1952, the now -called M-1 design was tested and in evaluating the test results of the construction of a small, leaf lace -driven helicopter was decided.
Development
The results of the testing of the M -1 was the OKB Mil passed that in 1953 began designing a small, four-seat helicopter, which are used as " air taxi " and should help bridge the vast distances within the Soviet Union. Military was close to use as an artillery observer. A first model was launched in March 1958 by a state commission in inspection, which placed an order for five of the W-7 as indicated ( for Wertoljot, Helicopter ) helicopter. To stabilize the W-7 should be fitted to the tail boom with a vertical fin, but were conducted in TsAGI wind tunnel tests that this was not sufficient for this purpose. It has therefore been replaced by a tail rotor, which was connected to the main rotor and as it is driven therethrough. The two-bladed main rotor got his hand on the ends of each one AI -7 jet engine whose fuel supply was ensured by contained in the leaves containers. Construction of the prototype began in 1959. On 10 February 1962, a first test flight took place, because of the new drive system and unmanned floating on ropes just above the ground. Here, by the unbridled power delivery of the engines, the rotor blades were deformed. The tests were therefore interrupted, eliminates the damage and cultivated new, developed by ZIAM MD-3 engines. After over three years of interruption, the trial in April 1965 was finally resumed. Meanwhile spacing was of a use of the blade tip drive but already been taken. The test series was therefore canceled and set the project. The only built W-7 can be seen in the museum of the Russian Air Force.