T he Fighter N07211 was proposed by two young engineers I.F.Florov and
A.A.Borovkov. The VVS head Ya.I.Alksnis expressed his support and personally
accepted the mockup of 7211. After brief conversation with GUAP leadership
designers received production base, finished the project and in May 1937
the 7211 rolled out.
The 7211 was a fixed-gear biplane of original construction. First, it was very small (wing area only
18m2!) Cockpit was moved almost to the tailfin root, but pilot's sight was surprisingly good. Upper
wing was installed on four short struts with tension steel tapes. No other struts or wires were installed between the
wings, providing very clean design.
This was allowed by novelties in the wing design. The wing (and tailplane) had a smooth aluminum skin with one-two
layers of 1mm corrugated aluminum under it. Such a construction allowed to use wing skin as a constructive element,
allowing to minimize weight of spars and ribs. Wing turned to be very light - just a 12.23kg/m2.
Forward section of the fuselage had steel tube frame covered with duralumin skin. Tail section - wooden monocoque
similar to the I-16.
Landing gear used same design as I-15, with airdynamic fairings. The
three-blade propeller was driven by M-85 engine in NACA cowling. Pilot's
seat was not armored. 7211 had provision for four ShKAS machineguns with 2200
rounds of ammunition (not installed on the prototype).
First flight took place on May 23, 1937. Factory pilot L.M.Maksimov
performed 21 flights. Once the 7211 was flown by P.M.Stefanovsky. Factory trials passed without problems. Maneuverability
of the 7211 was intermediate between the I-16 monoplane and
I-15 biplane, but climb and ceiling were superior to both.
State trials started on June 21, 1937. The very first flight ended with
a crash. Pilot E.Yu.Preman circled the field once (as demanded) and touched down - but changed his mind and pushed for
another circle. On the very edge of the airfield engine died out... low altitude left no room for return or safe landing.
Nonetheless, in May 1938 designers were invited for meeting with
Aviation Industry leadership, and in Fall 1938 they were assigned to bring
the '7211' to production state. Following aircraft were designated I-207 (product
'7').
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