The Helio AU-24 Stallion was an American armed gunship, counter-insurgency, and utility transport developed for the United States Air Force. A total of 20 were built during the Vietnam War, with most of the aircraft being later sold to the Khmer Air Force.

The Fairchild AU-23 Peacemaker is an American armed gunship, counter-insurgency, utility transport version of the Pilatus PC-6 Porter for the United States Air Force. A total of 35 were built under license in the United States by Fairchild Industries, for use during the Vietnam War in the early 1970s. All aircraft were later sold to the Royal Thai Air Force.