Technical data
Type IL-400a
Function fighter
Year 1923
Crew 1
Engines 1*400hp M-5/Liberty

IL-400a N.N.Polikarpov, I.M.Kostkin, A.A.Popov

Monoplane, fighter powered with license-built Liberty-400 engine. It was quite non-typical design for Russia, where biplane and parasol fighters dominated until 1933. Project started in January 1923. Team (N.N.Polikarpov, Yu.G.Mouzalevskij, A.A.Savinykh, V.A.Tisov, V.D.Yarovitsky) worked on the aircraft with several interrupts, thanks to frequent re-organizations and re-assignments of leading designers. They often had to work in late hours.

Wooden design with fabric cover of the wings and tail surfaces. Plywood skin of the fuselage (up to 4mm thick) was included in airframe structure. Radiator was borrowed from D.H.-9.

'Silhouette' was somewhat crude, but the worst was very rear location of the CoG. As a result aircraft was disappointing. Flight tests started in August 2, 1923 and aircraft was unable to 'raise the tail'. Main gear was moved backwards and on August 14 tail was pulled up.

August 15(16,23) IL-400 made 'candle' - steep climb. Pilot's seat was broken, pilot (K.K.Artseulov) decreased power - and aircraft fall down. (according to V.B.Shavrov it occurred in May 1923). All flight lasted 21 sec, aircraft was almost completely destroyed.

Wind tunnel study of a model with similar rear location of the CoG (52% of wing chord) proved intrinsic instability of the aircraft.



  • "History of aircraft construction in the USSR", Vol.1 p.353-354;

  • More Links...
  • I-1
  • I-1 at Virtual Aircraft Museum
  • IL-400, Polikarpov

  • Modified December 2, 1997 Back to
    Main Gate