Shadow Children of Saigon by Robert Fulton

Three children of mixed-race, referred to by the surrounding culture as "children of the dirt" as they are not considered in anyway Vietnamese literally fight to survive on a daily basis in the last years of the American War. Almost mystically, fate brings an American helicopter medic into their sphere. His good heart strives to help them survive the perils of war and hatred. Helicopter rescue scenes and dangerous journeys ensue.