Fairchild AU-23 Peacemaker
The Fairchild AU-23 Peacemaker is an American armed fixed-wing counter-insurgency and utility transport aircraft developed from 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.
Source: Wikipedia — Fairchild AU-23 Peacemaker (CC BY-SA 4.0)