The helicopter explodes as the others move to avoid
Battlefield vietnam is a game that involves both strategy and team work. It is oriented about trusting your team mates (though that can be a hassle when they cant fly properly; LOL). The strategy of commanding your troops to surround a VC/NVA bunker then telling them to destroy it is the art of command. Though this is a simulation of war, it gives you the impression that you are in the combat zone because of the graphics and such.
Here some links for official sites (marked with a *) and my sites about the game (Marked with **).