Battuta, that's not a realistic simulation...

However, if you're going for a mixture of realism and simplified physics, ARMA 2 isn't bad. Although the little things demonstrated that it wasn't going to take the cake for accuracy (as well as being inherently simplified for integration into what ARMA truly is - an infantry simulation), the overall
feel of flight is very lively, which makes it highly enjoyable. That said, it's worth a look - you can get the demo on ARMA's website.
As far as realistic flight without the combat, you might consider X-Plane, which is constantly improving. You might hold off on buying it though, as X-Plane 10 should be coming along in the near future. And then you might want to wait until the price comes down/the bugs are sorted out. Whatever you do, X-Plane is a great investment... And should you want to fly a chopper that you can't get or doesn't exist,
you can always make your own.
