Technical data
Type I-4 I-4 'Zveno'
Function Fighter Parasite Fighter
Year 1928 1930
Crew 1 1
Engines 1*480hp M-22 1*420/525hp Gnome-Rhone Jupiter-VI
Wing Span 11.40m 11.40m
Length 7.28m 7.28m
Wing Area 23.80m2 19.80m2
Empty Weight 978kg 940kg
Maximum Weight 1430kg 1362kg
Wing Load (kg/m2) 60 69
Power load (kg/hp) 2.97 3.25 (2.59)
Speed at 0m 220km/h 253km/h
Speed at 3000m 231km/h 245km/h
Turn time 13sec 11sec
Takeoff Roll 90m 7sec -
Landing Roll 210m 19sec -
Flight Endurance 2h18min 2h18min
Range 840km 686km
Ceiling 7000m 7650m
5000m 14.3min 10.9min
Fuel+Oil 236+25kg
Guns 2*mg7.62mm 2*mg7.62mm
Bombs 4 small bombs under lower 'wing'

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

Two photos (16k each) of 1/72 Encore model of the I-4 'Zveno' (this kit includes also provision for ANT-5 prototype and I-4), built by Alexandre Savine

Sesquiplane single-seat fighter. I-4 differed from ANT-5 by redesigned (to decrease drag) engine howling, and increased tailfin. Quality of production aircraft suffered even more than the pre-production models. I-4 could not be considered among the World advanced fighters any longer. It became obvious that fighter skin has to be smooth, and strut/wing joint have to be covered with fairings, as well as the wheels.

Nonetheless, I-4 was in production during 1927- 1932 and in service with airforce during 1928- 1933. Some I-4s were rebuilt (in 1933) to serve as a parasite fighters for V.S.Vakhmistrov Zveno experiments. Lower wing was cropped to 0.5m (each half) to make takeoff from TB-1. Aircraft handling became more demanding.

In 1931 experimental parasol monoplane I-4bis was built and flown.

Several attempts were taken to increase firepower of the I-4. Preliminary tests were performed with additional machineguns on the upper wing, but those even did not enter trials. In December 1931 pair of recoilless cannons (76mm DRP) were installed under the upper wing, far of the propeller arch. Despite an accident with an explosion of one DRP, trials continued until 1933.

Floatplane version was under construction during Summer 1931 (floats by AGOS), but at the time the concept of floatplane fighter was found obsolete. I-4 floatplane was not finished.

In 1932 GDL (under the VVS order) started evaluation of liquid fuel rocket booster for the fighter. Project head - V.P.Glushko. Two ORM-52 rocket engine under the lower wing, providing 300kg thrust during 60sec.

In 1935 AGOS performed trials with rocket boosters, installed on the upper wing. Six solid-state rockets (5kg each, including 1.3kg of a powder) were installed in arrays of 3. Burning time was 2.5sec, providing at the beginning of trials 250kg of thrust each. During those experiments thrust was increased to 450...500kg per rocket. Later those tests continued on the I-15 airframe.

The I-4 was the first mass built Soviet all-metal fighter;

369 were built.


  • ANT-5
  • I-4 'dubler'
  • I-4 pre-series

  • I-4bis
  • I-4 'Zveno'
  • I-4 with extra guns
  • I-4 with 76mm DRP
  • I-4 floatplane
  • ReferencesLinks
  • "History of aircraft construction in the USSR", Vol.1 p.366-368;
  • I-4
  • ANT-5 / I-4 at the Virtual Aircraft Museum
  • ANT-5, Tupolev
  • I-4, Tupolev

  • Created January 2, 1997
    Modified December 27, 1998;
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