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The
TsKB-12 project emerged from Summer 1932 modern
fighter drawings by N.N.Polikarpov. The original layout had Taunend ring
covering the engine.
After mock-up tests in the wind tunel and several structure improvements,
question of mass production was raised even before completion of a prototype.
Two prototypes were built - TsKB-12 (with M-22 domestic analog of the Bristol
Jupiter VI engine) and TsKB-12bis for tests with US built Wright-Cyclone
SGR 1820-F-2.
Mixed design plane, using wing spars made of chrome-molibdenium steel
alloy, dural ribs, and mixed D1 aluminum alloy/fabric skin. Fuselage was
built of pine longerones and frames, covered with birch cross-graine glued
strips 4.0mm-2.5mm thick. Tail plane and ailerones had dural frame and
fabric cover. Gear retraction system employed cables, since hydraulic systems
were not in wide use yet. Enclosed cockpit with forward-sliding canopy
was a novelty, and later pilots often flew the TsKB-12, I-16 Type 4 and
5 with open canopy.
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20k b/w drawing
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56k b/w photo of TsKB-12 during first Winter trials.
Number of problems were revealed during flight tests (December 30,
1933 - Spring 1934), specially with landing gear (to be cranked up and
down manualy) and airplane stability. Short fuselage, together with excellent
maneuvrability provided serious handling complicity, and test-pilot's (V.F.Chkalov,
V.K.Kokkinaki, V.A.Stepanchenok) conlusion was that this is a fighter for
skilled pilots only.
In early tests prototype was unarmed, it carried dummy barrels in wings.
During trials rudder area was increased and Hamilton-Standard 3-blade propeller
was replaced by domestic V-22 two-blade unit. In early 1934 engine cowling
was redesigned to solve overheating problem.
28k b/w TSKB-12 with reconfugured engine cowling
and domestic propeller (I-16 with M-22 engine) from "History of aircraft
construction in the USSR" by V.B.Shavrov, Vol.1 p.493
The TsKB-12 went into production in mid 1934, and few hundred of this
aircraft were built with the M-22. TsKB-12 was followed by the I-16 Type
4 with several design changes. Despite outstanding performance of the aircraft,
N.N.Polikarpov started to work on the second protoype ('Dubler' TsKB-12bis)
with more powerful engine before the first TsKB-12 took off.
| References |
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"History of aircraft construction in the USSR" by V.B.Shavrov,
Vol.1 p.491-494;
'Polikarpov Fighters in action, Part 2' by Hans-Herri Stapfer.
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Technical data |
