Johnson Air Base Site (JASDF Iruma Air Base)

Iruma Air Base, located in Sayama and Iruma Cities in Saitama Prefecture, traces its origins to 1938 when the Imperial Japanese Army established Irumagawa Airfield as the dedicated training facility for the Army Air Force Academy (陸軍航空士官学校). The academy had relocated from nearby Tokorozawa, and the new airfield was completed in January 1940 with a full-length runway and training infrastructure.

During World War II, the base primarily served as a pilot training academy, with cadets flying Kawasaki Ki-10 biplane trainers painted in distinctive orange livery. As the war intensified, operational units were also stationed here — notably the IJAAF 14th Sentai, which operated Mitsubishi Ki-67 "Hiryu" (Flying Dragon) medium bombers. In the desperate final months of the war, the base was associated with preparations for Yokosuka MXY-7 Ohka rocket-powered kamikaze aircraft missions against the approaching American naval forces.

Following Japan's surrender on August 15, 1945, the United States Army Air Forces Fifth Air Force occupied the airfield on September 25, 1945, establishing it as a major American military installation in the Kanto region. The base was renamed Johnson Air Base in honor of Lieutenant Colonel Gerald R. Johnson, the celebrated commander of the 49th Fighter Group who had achieved 22 aerial victories in the Pacific Theater, earning the nickname "Jungle Ace." Johnson was killed on October 7, 1945, when his B-25 Mitchell crashed while attempting to land at Irumagawa during a typhoon.

During the Korean War era, Johnson Air Base served as a significant staging and support facility for U.S. operations. The base hosted various fighter and support units throughout the 1950s. In June 1962, the USAF's 41st Air Division relocated to Yokota Air Base, ending major American operational use. The last U.S. Air Force facilities were closed in September 1978, and the base was completely returned to the Government of Japan.

Today, JASDF Iruma Air Base hosts the headquarters of the Central Air Defense Force (中部航空方面隊) and multiple squadrons. It is renowned for its annual air show held on Culture Day (November 3rd), which attracts hundreds of thousands of spectators and features the Blue Impulse aerobatic team. The nearby Johnson Town district in Iruma City preserves American-style housing from the occupation era as a cultural heritage area.