I-1 N.N.Polikarpov, I.M.Kostkin, A.A.Popov

56k b/w IL-400b prototype from "History of aircraft construction in the USSR", Vol.1 p.354

After tests of IL-400b and IL-3 decision was made to launch aircraft into production under designation I-1. Aircraft built of Zavod-1 (Factory-1) were not all identical. Just first batch of 13 aircraft included 3 subtypes.

All aircraft were tried at NOA, including spin behavior. It was found (according to test-pilot M.M.Gromov) that CoG is still to far behind (44% of the wing chord) of optimal and spin escape can not be considered guaranteed. During those tests he was forced to abandon the aircraft with parachute (first case in the USSR). It took place on June 23, 1927. Other test pilot - A.I.Sharapov - get out of flat spin on minimal altitude by lucky occasion only.

As a result I-1 was considered dangerous to fly and was not accepted for service. It was the end of first series low-wing monoplane in Soviet/Russian history.

30 built.

Predecessor(s)
IL-400a	IL-400b	IL-3