 On 13 January 1971 at 0001, MACS-4 made its last tactical transmission in support of operations during the Vietnam War.During its time in Vietnam utilizing MTDS, MACS-4 controlled or assisted 472,146 aircraft.Even though MACS-4 departed Vietnam on 31 January 1971 it maintained a small detachment of twenty Marines on top of Monkey Mountain to man the AN/TYQ-3 - Tactical Data Communications Central (TDCC).