 It maintained Detachment 1 in Southeast Asia during the Vietnam War between 1965 and 1970.Detachment 1 returned to Southeast Asia in 1971 to support Operation Linebacker and Operation Linebacker II operations.On 15 August 1973, Detachment 1 EC-121s flew their final combat mission, and on 1 June 1974, the EC-121 was permanently withdrawn from Southeast Asia.