American units in Iraq have learned that their most flexible weapon is the helicopter. By flying low, fast and not hovering much, most ground fire can be avoided. This was a lesson learned in Somalia over a decade ago, but had to be relearned in Iraq and Afghanistan. The choppers provide rapid transportation, good observation of the battlefield and firepower when you need it most. The speed is essential in catching ambushers, either in the act, or when they try to escape. When a tip is received, a raid can be carried out quickly enough to catch culprits who may be moving around a lot. 

The main problem with the helicopters is that there are not enough of them, and you cannot use the ones you have as often as you would like. Like all aircraft, helicopters require a lot of maintenance between flights. You cannot afford to have things go wrong with your engines or other equipment while you are up in the air, the maintenance must be done. Therefore, choppers in Iraqi average about 65 hours in the air each month. Some you can push to a hundred hours or so a month, but this depends on your supply of spare parts, and the stamina of the ground crews. Push the maintenance troops too much and they will make mistakes. 

The usefulness of helicopters helps explain the tremendous popularity of UAVs. While only good for reconnaissance, they are cheaper than choppers, dont put pilots at risk and are a lot cheaper to buy and operate. Hundreds of additional UAVs are headed for Iraq and Afghanistan. But there are some jobs, like transporting troops and delivering pinpoint firepower, that only helicopters can do well in a rapidly changing battlefield situation. While there are some larger UAVs (like Predator) that can carry weapons, there are not many of these. Fixed wing aircraft, like the A-10, or higher flying bombers, can also deliver smart bombs and other pinpoint fire. But the ability of helicopters to be low and right in the action is a tremendous advantage. In combat, seconds count, and often only helicopters or UAVs can respond quickly enough to make a difference.