The advance echelon of USSAG/7AF moved from Tan Son Nhut Air Base to Nakhon Phanom on 29 January 1973. Transfer of the main body, drawn largely from the operations and intelligence sections of MACV and Seventh Air Force, began on 10 February. USSAG was activated on 11 February 1973 under the command of commander of MACV, but at 08:00 on 15 February, USAF General John W. Vogt Jr., as USSAG/7AF commander, took over from MACV control of American air operations. U.S. air support operations into Cambodia continued under USSAG/7th AF until August 1973.