The SK-2, flown in October 1940, had a similar small-area wing and 1,050 hp Klimov M-105 twelve-cylinder liquid-cooled V-engine, but an orthodox cockpit, conventional carburetor and oil cooler air intakes, revised vertical tail surfaces and an armament of one 0.303 in (7.62 mm) and two 0.5 in (12.7 mm) machineguns.
The SK-2 was of all-metal construction with dural pressed sheet stressed wing skinning and a semi-monocoque fuselage. Flight test results were allegedly promising, but not sufficiently so to warrant displacing established fighter types in production.
Span: 23 ft 11.5 in (7.30 m)
Length: 27 ft 2 in (8.28 m)
Height: 8 ft 6.4 in (2.60 m)
Wing area: 103 sq.ft (9.57 sq.m)
Weight empty: 4,0784 lb (1,850 kg)
Loaded weight: 5,070 lb (2,300 kg)
Max speed: 401 mph (645 kmh) at 8,860 ft (2,700 m)
Climb: to 16,405 ft (5,000 m) 4.3 min
Endurance: 0.75 hr)