It also does not help that both sides have higher technology MANPAD systems than the survivability systems on the aircraft. Also the antiquated tactics used by both sides at the beginning of the war did not help reduce the numbers of casualties. Until someone can show me real data about how many missions are flown per aircraft lost I am not willing to write off an entire concept of operation. With Youtube rational we ought get ride of tanks and artillery and air defense. Even infantry might be questionable.
@Kiltonge - what they do not tell you about that statistic for U.S. Army losses in Vietnam are how many of those helicopters were recovered, fixed, and shot down again. There were some helicopters, that over their lifespan, had been shot down three or four times.