Overview: One of the great battlefield innovations developed by the United States armed forces in its effort to defeat a skilled and often elusive enemy in Vietnam was air cavalry--light infantry deployed by helicopters. Always outnumbered, and fighting in a totally hostile environment, American soldiers had to rely on technology and new techniques to contain the enemy. The highly mobile helicopter troops who formed the Air Cavalry used quick-response techniques to counter the huge odds against which they fought daily. As a concept, air cavalry was innovative. As executed by air cavalry units, it was phenomenal, and the 1st Cavalry Division in Vietnam was the quintessential air cavalry organization. Its prominent and evolving role began in the Ia Drang Valley in 1965, and one of its greatest achievements came at Khe Sanh in 1968.