During World War II, Madras Airport served as the Madras Army Airbase, where local skies filled with B-17 Flying Fortresses, C-47 transports, P-39 Air-Cobras, P-38 Lightning fighters, and small observation and liaison planes, and Jefferson County personnel served as pilots, crew members, and military staff. In 1943, Major Joseph Arnold, the first commander of the Madras Army Air Field, announced that its mission would be combat training for aircrews in Boeing B-17-F Flying Fortress bombers in the 318th Squadron of the 88th Bombing Group. Runways, taxiways, hard stands, hangars, auxiliary buildings, and barracks were built or refurbished rapidly, including a new 7,400-foot runway reportedly the longest in America at that time, while the City of Madras, with a population of 412 in 1940, was strained by the arrival of several hundred officers, pilots, GIs, and Army construction workers in the first months of 1943. In February 1944, the Second Air Force was replaced by the Fourth Air Force, shifting emphasis from bomber training to preparing fighter pilots, though B-17s continued to use the base; in early March 1944, P-39Q Air-Cobras of the 546th Fighter Squadron of the 475th Fighter Group arrived, and later in 1944 they were joined by P-63 King Cobras and Lockheed P-38 aircraft. In September 1944, the base's main task shifted to maintenance, bringing another influx of personnel, and after that order flight instruction effectively ended, the busy skies over Madras cleared, and by VJ Day on September 2, 1945, the brief intense era of Madras' military airbase was already over. In November 1945, the base was declared surplus to the needs of the Army, and after local officials campaigned for transfer with support from Wayne Morse and Colonel Joseph Arnold, Washington announced on April 3, 1947, that the airbase was officially transferred to Madras and Jefferson County. Two large hangars remained in service, spacious enough to house a B-17 and carefully maintained, and penciled graffiti still survived on the walls of the old ready room in the airport's South Hangar, recalling the wartime period.