Based on what I have read about the game on this forum and in the previews, there will be about 40 flyable planes in the game.
Of the 40 flyable planes, 12 Allied planes will be featured in the Single player historical campaign mode.
All 40 planes will be flyable in the Single player "Instant Action" (Training) mode as well as the Multiplayer mode.
See here:
http://forum.1cpublishing.eu/showthr...ng+mode&page=2