The U.S. Department of Defense predicts that ground forces of the future will wage tomorrow 19s wars by replacing large numbers of personnel and organic firepower for advanced technology and superior maneuverability. Those forces must be prepared to face an unconventional enemy who will operate in small, lethal units interspersed with the civilian population rather than facing coalition forces with massed formations. This scenario of blurred lines of battle and difficulty determining friend from foe resembles very closely what the U.S. military faced in Vietnam. This paper will address the successes and failures of United States airborne FACs, particularly in Vietnam, and whether combat lessons learned were passed from service to service or historically from conflict to conflict. The FAC mission has not significantly changed since the end of the Vietnam War, and a thorough study of operational and tactical lessons learned by those aircrew will significantly enhance today 19s FACs ability to find and destroy dispersed enemy forces in a wide array of environments.