Polikarpov I-1
The Polikarpov IL -400 (Russian Поликарпов ИЛ -400) was the first series cantilever monoplane fighter aircraft of the Soviet Union.
Development
Nikolai Polikarpov developed this type along with I. M. Kostkin and A. A. Popov in 1922. Was powered by an American Liberty engine, after which the aircraft received its name (I = Istrebitel ( fighter ) L = L Liberty -400 ). On August 15, 1923, the first flight, which, however, due to the displaced center of gravity too far back after 21 seconds ended with a crash, the test pilot K. K. Arzeulow was seriously injured was. After extensive wind tunnel tests in TsAGI then the slightly modified IL- 400B, which first flew on July 18, 1924 was born. The state flight testing of two built two prototypes (designation for No. 2 was IL-2) lasted until 15 October of the same year and was well above average levels. Then the series production of 33 aircraft was ordered. As drive the now reconstructed as M- 5 Liberty engine was used. Therefore, the machines were also produced under the name of I-1- M5, this was later changed to the acronym I-1 changed. However, the production ended after 18 copies, because the plane was very difficult to fly. It had a strong tendency to tipping and was difficult to bring out of the tailspin. Finally, it was simply classified as dangerous and prohibited the extradition to the Air Force.
Technical Description
The Il -400 was a cantilever low- wing monoplane of all- wood construction. The front body with a square cross-section was sperrholzbeplankt, the rear body member and the structure was covered with fabric; in the I-1, however, passed the ribs from smooth and the outer skin of corrugated aluminum - similar to those built by Junkers corrugated metal aircraft. The tail unit was manufactured in standard design and also self-supporting. The aircraft had a rigid main landing gear with through axle and a tail skid at the rear.