Plot: Drawing on its first experiments with helicopters in Korea, the Army in Vietnam came to rely almost entirely on the helicopter for medical evacuation. The Dust Off and Medevac helicopter ambulance units tested and perfected for medical use the Army's new helicopler, the UH-1 ("Huey" Iroquois), and developed several new devices, especially the hoist, that helped save thousands of American and allied lives between 1962 and 1973