As with the civilian version, the Skymaster was a low-cost twin-engine piston-powered aircraft, with one engine in the nose of the aircraft and a second engine in the rear of the fuselage. The push-pull configuration meant a simpler single-engine operating procedure due to centerline thrust compared to the common low-wing mounting of most twin engine light planes, and also allowed for a high wing, providing clear observation below and behind the aircraft. During the Vietnam War, the Skymaster was intended to be replaced in the forward air control (FAC) mission by the OV-10 Bronco, but the O-2A maintained a night mission role after the OV-10's introduction due to the OV-10's high level of cockpit illumination, rendering night reconnaissance impractical. The O-2 was phased out completely after additional OV-10 night upgrades.

Markings for:

• Cessna O-2A Skymaster, U.S. Air Force s/n 68-11067, Forward Air Control, Laos, 1970
• Cessna O-2A Skymaster, U.S. Air Force s/n 68-10999, Fit Lt David Robson (RAAF), 19th TAAS USAF, Vung Tau, Vietnam, 1969
• Cessna 0-2 A Skymaster, U.S. Air Force s/n 68-11013