Technical data
Type I-4bis
Function Experimental fighter
Year 1931
Crew 1
Engines 1*480hp M-22
Length 7.28m
Wingspan 11.4m
Wing area 19.8m2
Empty weight 973kg
Loaded weight 1385kg
Wing Load (kg/m2) 70
Power load (kg/hp) 2.88
Speed at 0m 268km/h
Turn time 12sec
Flight Endurance 2h18min
Ceiling 7000m
1000m 14.0min
Fuel+Oil 236+25kg
Guns 2*mg7.62mm

I-4bis by P.O.Sukhoj/ A.N.Tupolev

15k b/w photo from the Virtual Aircraft Museum

Monoplane variant of the I-4. Leading edge slats (half of the wing span) were controlled by the pilot. Engine cowling was replaced by Townend ring with individual fairings over cylinder heads.

I-4bis was rebuilt from series I-4 for research purposes and flown in 1931. It was 10km/h faster than production aircraft, but suffered some losses in maneuverability. Other parameters remained unchanged. Slats proved to be helpful, but manual operation required too much attention from a pilot. It was found that slats should be made automatic... and the concept was abandoned until 1940.



  • "History of aircraft construction in the USSR", Vol.1 p.367;
  • ....

  • Created December 28, 1998 Back to
    Main Gate