Borovkov-Frolov I-207

In 1937, Aleksei A Borovkov and Ilya F Florov established an experimental design bureau as OKB-7 with the object of creating the smallest possible practical single-seat fighter. The first prototype was completed before the end of 1937, and was of heavily-staggered cantilever biplane configuration with duraluminskinned light alloy wings, a fuselage of mixed construction (the forward portion being a duraluminskinned welded steel-tube structure and the aft portion, which included the cockpit, being a wooden monocoque with plywood skinning) and wooden tail surfaces. Power was provided by an 850hp Mikulin M-85 14-cylinder radial. Favourable test results led to two further refined prototypes being built as I-207s, these having Shvetsov M-62 and M-63 engines respectively and each carrying an armament of four 7,62-mm ShKAS machine guns. A pre-production series of four I-207s was ordered in 1938, one being powered by the 1,100hp M-63 nine-cylinder radial, two having the 1,000hp M-62 nine-cylinder radial and the fourth having a geared M-63R engine and a side-hingeing cockpit canopy, all having retractable main undercarriages. The I-207/M-63 attained a speed of 298 mph (480 km/h) at 14,765 ft (4 500 m) during State Trials in the summer of 1939, but the appearance of more advanced fighters resulted in the 1-207 being discarded, although both I-207/M62s were allegedly employed operationally against the Finns during 1939-40.

3-View

A three-view drawing (1690 x 1273)