This two-seater liaison aircraft was used by the U.S. Army during World War II, and is one of ten aircraft taken over by the ROK Army Aviation Unit, the predecessor of the ROK Air Force, from the U.S. Air Force in September 1948. It was the first military aircraft owned by the country. Early in the Korean War, L-4 planes were used to drop bombs on the enemy (by the crew member in the rear seat). They were also used effectively in the suppression of rebel troops during the Yeosu-Suncheon Rebellion and communist guerillas hidden on Jirisan Mountain. Later, they were used to transport Army unit commanders and train pilots and engineers. They were retired from active service in 1954 following the purchase of L-19 planes.