Thank you very much for your help Genghis ! I knew somebody could give me some clues around.
Excuse my " amateur" approach of the problem !
IL2 is the Title of the mentionned Flightsim, but it allows the simmer to fly many a/c, not only the Illiouchine. Yak's, P39, ME109, FW190 , and so on, are among the flyable toys ! Graphics are beautifull and I will consider the flying envellopes as realistic (although I don't have any military flight experience ...)
Great fun !
Merci