The O-2A Super Skymaster was a push-pull twin-engine, three-seat, militarized version of the Cessna 337A Skymaster, affectionately known as the "Oscar Duck." This rugged aircraft was flown throughout Southeast Asia in a variety of Forward Air Control roles, including directing air strikes and conducting reconnaissance over the Ho Chi Minh Trail. Its four underwing hard points could carry a variety of rocket launchers and flares. The O-2A's standard load of 14 white phosphorus-marking rockets, combined with increased time over station and an upgraded communications suite, enhanced its ability to operate in the adverse weather of Southeast Asia. The O-2B was modified for psychological warfare operations by adding loudspeaker systems and leaflet dispensers. A total of 510 O-2As and O-2Bs were delivered to the Air Force by December 1970, and all O-2 Forward Air Control training was done at Hurlburt Field until December 1975.