Tak czy owak ciekawa historia. Przytaczam fragment maila Andrei:
The I-17 is a little mistery. In my opinion, it fought on the front. Here some details if you want to share with your friends.
The English Wikipedia says that it stopped at prototype stage:
http://en.wikipedia.org/wiki/Polikarpov_I-17
But it could be wrong. A book by Angelucci/Matricardi "Guida agli aeroplani di tutto il mondo" (Mondadori) that was quite a general reference here in Italy says that "it was produced and served in the conflict, but in a very limited quantity and only up to 1942" ("fu messo in produzione e servì nel conflitto, ma in quantità assai limitata e solo fino al 1942"). I am putting a Hungarian Fiat Cr42 falco in one of the next boosters and that ace downed two I-17 over Dniepropetrovsk (if there has been no mistake), details of the action here:
http://surfcity.kund.dalnet.se/hungary_ujszaszy.htm
Here it says that they fought in 1941:
http://www.aviation.ru/Po/
Here it even says that Hungarians used it in post-war period:
http://ww2photo.mimerswell.com/air/su/poli/po1-17.htm
Here it says that they have never been produced
http://mig3.sovietwarplanes.com/I-17/index.html
but that some Finnish pilot told to have downed them
Here it says that Slovak pilots reported meeting them in the same summer of the Hungarian ace (see paragraph "First campaign of the Slovak army at the Russian front"):
http://www.geocities.com/slovakaf/histo ... ry1.en.htm
Here you have a profile:
http://wp.scn.ru/en/ww15/f/1731/1/0/1
Source is an Osprey book, "50 Fighters 1939-1945' Aircam Aviation Series No.S18, Volume 2":
http://wp.scn.ru/en/ww15/f/1731/1/0
So... Not a whidely used plane, but worth a bit of research IMHO.