The location is an NVA base about 50km from a town called Duc Duc. The war was going badly in 1971. The NVA leveled Duc Duc for being friendly to Americans and they basically massacred the population. The concept of fast attack teams was coming into vogue. Choppers had been mostly used to ferry troops and material in and out areas. Gunships had been mostly used to support ground troops and fly cover. The attack teams would not carry troops, they would be used as a means to disrupt the enemy. Do not mistake the elegant Apache gunships of today with a UH class ship with miniguns and rocket launchers hung off the sides. The there was no targeting system, you just put whatever you wanted to hit in the crosshairs and let loose. The pods cut your speed down and if the port and starboard rockets failed to fire together, it would turn you sideways. The new ships are elegant and the drivers are better trained, and even today in Iraq, the bad guys scatter when they hear the rotors. If you are low enough, they don't hear you till its too late.