The 20th Tactical Air Support Squadron (20th TASS) was activated during the Vietnam War to provide forward air control (FAC) and close air support coordination for U.S. and allied ground forces. Established in 1965, the squadron initially operated the O-1 Bird Dog and later transitioned to the O-2 Skymaster and OV-10 Bronco aircraft, flying dangerous low-level missions to identify enemy positions and direct airstrikes. The 20th TASS played a crucial role in supporting operations such as Operation Rolling Thunder and interdiction missions along the Ho Chi Minh Trail. After the Vietnam War, the squadron continued FAC missions before being inactivated in 1972.