Polikarpov I-3
The Polikarpov I-3 (Russian Поликарпов И -3) is a single-seat biplane fighter. It was built in the second half of the 1920s and was produced in a quantity of 399 copies and used by the Soviet forces.
History
As a starting model of this design was Nikolai Polikarpov the two-seat fighter DI - 1, the test was interrupted by a crash due to strength deficiencies of the cell and not resumed.
The I-3 was equipped with an inline engine, in contrast to the parallel development of I-4 by Pavel Sukhoi, which received a radial engine. Through these two engine types should be found which property approached the more important function in a fighter plane. Therefore Poli Karpov's construction had due to driving at a high speed while Sukhois I-4 achieved a better maneuverability.
The dummy of the machine was completed on 14 May 1927, the first flight of the prototype was followed a year later on May 4, 1928. Since the testing was uneventful and the guy was maneuverable and easy to fly, was preparing to mass production before the 1929 started off. The I-3 served five years in the first line and was subsequently discharged to the school units.
Technical Description
The I-3 had a pine wood finished with Sperrholzbeplankung skin fuselage with oval cross section. The wings had two box-shaped main spars with plywood ribs. The tail unit consisted of a cloth covered with duralumin frame. The rigid main landing gear was provided with a Gummipufferung and could be replaced by snow sled in the winter. At the rear, there was a tail skid. During the first series of machines were I-3 still equipped with English Vickers machine guns and German BMW Viz engines, upgraded one of the later samples with PW -1 MG's and M -17 engines under license.