 Trần Hanh joined the Vietnam People's Army in September 1949 and became a student of the Lê Lợi School for Officers and later Nguyễn Huệ School in December 1950.In his early career, Trần Hanh often served as political commissar ("chính trị viên") of various military units, he was appointed political commissar of the 23rd Company of 680th Battalion, 48th Regiment, 320th Division in February 1954 and afterwards deputy political commissar of the 680th Battalion in June 1954.In September 1956, Trần Hanh was chosen to study to fly the Mikoyan-Gurevich MiG-17 in a school of People's Liberation Army Air Force in China.