i haven't tried flight sim, how old is this game? if its just a recent game, i doubt that a 220 can max it out? are you sure it's the highest setting? gt220 is really low, even back in its day. if this was a gtx260 then ok.
but comparing the cards, just check the price and you'll get the idea
the game was released way back in 2006 (was it 2007?) if i am right. nevertheless its safe to say that he can max the settings if he plays way below 1080p and get 60+fps.