The defoliant Agent Orange was sprayed across areas of South Vietnam between 1962 and 1971 as part of Operation Ranch Hand during the Vietnam War. The Operation aimed to deprive the Viet Cong of cover in jungle areas and damage their capacity to feed themselves by destroying crops. In nine years, an estimated 18 million gallons of herbicides were dropped onto the jungles and mangrove swamps of South Vietnam.
Although airlifting herbicides was discussed before Operation Ranch Hand got underway, Agent Orange was transported to Vietnam by ship. The chemical was stored in barrels marked with an orange stripe, giving rise to the name by which the toxic defoliant is best known.
The herbicide was delivered by C-123 aircraft. Originally designed to transport troops and cargo, the C-123 aircraft dated from the immediate post-WW2 years, but it became a crucial player in the conflict in Vietnam. Initially the aircraft were fitted with MC-1 dispensers, but these proved inefficient. From 1966 onward, the C-123s used AA 45Y-1 Internal Defoliant Dispensers that, with a pump and spray booms on each wing and the aircraft’s tail, could cover a wider area of jungle in a single pass.
- Air Force Historical Support Division: Factsheets, Operation Ranch Hand
- Department of Veterans Affairs: Public Health, Facts About Herbicides
- Operation Ranch Hand, the Air Force and Herbicides in Southeast Asia 1961-91; William A. Buckingham
- National Museum of the U.S. Air Force: Factsheets, Fairchild C-123K Provider
- Environmental Science and Pollution Research: Environmental Fate and Bioavailability of Agent Orange; Alvin L. Young et al.
- Keystone/Hulton Archive/Getty Images