First U.S. Air Force plane crashes in South Vietnam. - Feb 02, 1962 - HISTORY.com

The first U.S. Air Force plane is lost in South Vietnam. The C-123 aircraft crashed while spraying defoliant on a Viet Cong ambush site.

The aircraft was part of Operation Ranch Hand, a technological area-denial technique designed to expose the roads and trails used by the Viet Cong. U.S. personnel dumped an estimated 19 million gallons of defoliating herbicides over 10-20 percent of Vietnam and parts of Laos from 1962 to 1971. Agent Orange–so named from the color of its metal containers–was the most frequently used.

The operation succeeded in killing vegetation but not in stopping the Viet Cong. The use of these agents was controversial, both during and after the war, because of questions about long-term ecological impacts and the effect on humans who handled or were sprayed by the chemicals. Beginning in the late 1970s, Vietnam veterans began to cite the herbicides, especially Agent Orange, as the cause of health problems ranging from skin rashes to cancer and birth defects in their children. Similar problems, including an abnormally high incidence of miscarriages and congenital malformations, have been reported among the Vietnamese people who lived in the areas where the defoliate agents were used.