The helicopter is, as a combat aircraft, a death trap. They kill soldiers is combat and in training. A single round can disable one. They are tremendously difficult to maintain. The Russian helicopters in Afghanistan were savaged by Stingers we provided to the Mujahadeen. Remember Carter's rescue operation in Iran?

The geniuses in the upper eceholons of the Marines wanted to replace a dangerous aircraft with an insane one - the Osprey, which combines the worst elements of 'copters and planes. But, the thing seems to have died under its own weight.