Presenting problems with the SR’s retraction system, SA Kochierigin decided to find the quickest solution to the problem. The result was a new model called R-9 with fixed landing gear and faired wheels, which considerably affected performance.
Other changes included increasing the empennage area in order to improve the aircraft’s directional stability and the addition of a new turret in the gunner’s position.
The M-85 powerplant and three-blade propeller used on the TsKB-27 were retained.
The tests of the Kochierigin R-9 (Russian: Кочеригин Р-9) began in 1936 and in them it was possible to obtain a speed of 447 km/h, which despite the fixed gear was considered a good result. However, it was not possible to achieve stability in the three axes that also affected the TsKB-27.
As a result of the lack of stability, the complete cycle of tests could not be completed. The decision to start producing the R-9 at Factory No.1 was reversed. Some time later its competitor Nieman R-10 began to be produced.
R-9
Engine: 1 x 800 hp M-85
Wingspan: 12.00 m
Length: 9.90m
Height: 3.20m
Wing area: 24.15 m²
Empty weight: 1940 kg
Normal takeoff weight: 2730 kg
Top speed: 447 km/h
Cruising speed: 366 km/h
ROC: 633 m/min
Time to 5000 m: 8.7 min
Practical range: 840 km
Practical ceiling: 9000 m
Crew: 2
Armament: 2 x 7.62mm ShKAS mg wings / 1 x 7.62mm ShKAS mg turret
Bombload: 400 kg
All Aero 