The first UH-1As were fitted to the 82nd and 101st Airborne Divisions – the dominant units of the US Army.
Vietnam battlefield was the first application and test site of the US Army’s “helicopter war” tactic. In total, the US equipped the Saigon government with 914 UH-1s, and 7,013 for the US Army. The UH-1s were used to transport troops, cargo, ambulance, and ground attack.
The first UH-1As were fitted to the 82nd and 101st Airborne Divisions – the dominant units of the US Army. It can be said that the UH-1 set a milestone for the creation of the “Air Cavalry” force of the United States. “Air Cavalry” used helicopters as vehicles of movement and combat, with extremely high maneuverability. The core of the “Air Cavalry” was the UH-1 helicopters. Each could carry a platoon with full equipment.
The Vietnam War was also where the US used the most UH-1 helicopters, with 4,000 in South Vietnam at peak. When the new UH-1A appeared, the South Vietnamese Liberation Army did not have many effective weapons and experience in dealing with this new US weapon. It caused a lot of difficulties for the opponent on the battlefield.
Over time, the Liberation Army found out the weaknesses of this helicopter. Their plan was ambush tactic. They patiently waited for the American helicopters to fall low to hunt for targets, or to land its troops, then they opened fire. Just a few shots hit the dangerous spot, it could destroy a UH-1 costing million dollars.
The first major failure of the “helicopter war” tactic was the Battle of Ap Bac on January 2, 1963. With only rifles and submachines, the South Vietnamese Liberation Army destroyed 5 UH-1s. On September 13, 1968, with two 12.7 mm guns and 40 bullets, the Liberation Army shot down 2 helicopters, one of which was carrying Major General Keith Lincoln Ware, Commander of the 1st Infantry Division, the “Big Red One”.
During Operation Lam Son 719, also known in Vietnam as 9th Route – Southern Laos Campaign, in 1971, a large number of 12.7mm anti-aircraft machine guns, in preparation for transfer into the South, were used to deal with the UH-1 low-flying helicopters. Due to the foggy weather in the West Truong Son mountains, the UH-1s had to lower their altitude to land. It immediately became a good prey for the anti-aircraft fire of the North Vietnam. According to some statistics, during the Operation Lam Son 719, 555 aircraft of the South Vietnamese and American forces were shot down, most of which were UH-1 helicopters.