Our pal Bill Ardolino has an extensive piece about helicopter warfare in Afghanistan over at Wired's Danger Room. Here's a taste:
...When Fleckenstein was out of position for a rocket shot, his “left seater,” Bravo Troop commander Capt. Joshua Simpson, fired his M-4 rifle out of the open side of the aircraft to maintain suppression. As soon as they cleared the target, Lacy swooped in and fired more .50-caliber machine-gun rounds, followed by another two rockets from Fleckenstein.
The flurry of explosions and bullets had the intended effect. First Platoon was no longer taking contact from the two insurgents, and the medevac helicopters had some breathing room to fly in and get the wounded...
Grab a drink and read the whole thing.