I really hate to be a...err...how do you put it...grammar nazi, but the description for the module when you look at it from the main menu says that the MiG-21 was made in the "1950'ies." I find this odd though, because if you say it out loud, it sounds like "nineteen fifty-ies."
If you don't want to fix it, that's fine, I just wanted to point it out. Thanks for reading, if anyone did.