now i wil like to mention a few excellent mods and addons for the Arma2 game.
1) RKSL Studios create high quality aircraft to be used in arma and arma2. http://www.rkslstudios.info/
2) Advanced Combat Environment, or ACE.
This is a mod that tweaks and enhances realism. It also adds weapons and tools.
There are tons more at http://www.armaholic.com/index.php.