Iruma Air Base 入間基地 Iruma-kichi | |||||||||||
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| Summary | |||||||||||
| Airport type | Military | ||||||||||
| Operator | JASDF | ||||||||||
| Location | Sayama, Saitama,Japan | ||||||||||
| Elevation AMSL | 295 ft / 90 m | ||||||||||
| Coordinates | 35°50′31″N139°24′38″E / 35.84194°N 139.41056°E /35.84194; 139.41056 | ||||||||||
| Map | |||||||||||
| Runways | |||||||||||
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| Source: JapaneseAIP atAIS Japan[1] | |||||||||||
Iruma Air Base (入間基地,Iruma-kichi) (ICAO:RJTJ) is aJapan Air Self-Defense Force (JASDF) base located in the city ofSayama,Saitama Prefecture, north of westernTokyo,Japan.
It was the airfield for theImperial Japanese Army Air Force Academy until 1945, when it became Johnson Air Force base of theUnited States Air Force during and after theoccupation of Japan. Johnson AB was completely returned to theGovernment of Japan in 1978.
Currently, Iruma Air Base is home to the Air Defense Command Headquarters Flight Group. Aircraft located at the base include theU-4,NAMC YS-11,T-4, andKawasaki C-1. Its annual air show on the November 3rdCulture Day holiday is a popular public event.
Iruma was established in 1937 by theImperial Japanese Army Air Force and namedIrumagawa Airfield. Opened in December 1938, it was the air academy for the Japanese Army Air Force, with its academy located at the nearby town. Mostly training aircraft operated from the base, includingKawasaki Ki-10 (Army Type 95 Fighter Model 1) biplanes painted orange. During World War II, the IJAAF 14th Sentai operatedMitsubishi Ki-67 medium bombers from Irumagawa. Attacked several times by USAAFB-29 Superfortress bombers, the last missions by the IJAAF were one-way missions usingYokosuka MXY7 Ohka purpose-built, rocket-powered, human-guided, anti-shipping kamikaze attack planes against American ships operating off the coast.

After the end of the war, theUnited States Army Air ForcesFifth Air Force headquarters onOkinawa was moved to Japan and was established at Irumagawa on 25 September 1945. The base was renamedJohnson Air Base in honor of Lieutenant ColonelGerald R. Johnson, the former commander of the USAAF49th Fighter Group who was killed in aB-25 Mitchell crash while on approach to Irumagawa during a typhoon.
Johnson Air Base was a majorUnited States Air Force base in Japan during the occupation years, then later during theKorean War and the 1950s. USAFFar East Air Force (Later Pacific Air Forces) command units based at Johnson were:
Operational USAF units based at Johnson were:


In August 1958, the JASDF Central Air Defense Force headquarters and Iruma Air Base were established at Johnson Air Base.[citation needed]
On 30 December 1960, the American facilities on the site of Johnson Air Base were re-designated as "Johnson Air Station".[citation needed]
In June 1961, Japan-US joint use agreement was established at Johnson.[citation needed]
In June 1962, the USAF ended its use of the air base, when the 41st Air Division headquarters moved to Yokota AB.[citation needed]
On 1 January 1963, the buildings of the air station were re-purposed for American family housing in Japan as "Johnson Family Housing Annex". The USAF 6102d Air Base Squadron became the host unit at Johnson, supporting the 6022d USAF Hospital and family housing civil engineering flights.[citation needed]
In November 1963, the base transitioned from USAF management to the JASDF.[citation needed]
On 28 June 1973, the USAF support units were inactivated, and most of their associated facilities were transferred back to the Japan Air Self-Defense Force. The major facilities retained by USAF at Johnson were the telecommunications center, telephone exchange, admin office, Aircom MW relay, electrical power stations, and HF antennas.[2] These facilities were transferred to the control of the475th Air Base Wing at Yokota AB and continuously operated by theAFCS 1956th Communications Group until MW tower relocated to the USAF Tokorozawa Transmitter Site, approximately 4 miles (6.4 km) southeast from Johnson.[citation needed]
In September 1978, the last USAF facilities were closed and completely returned to the Government of Japan.[citation needed]



The Iruma Air Show is held annually on the November 3rdCulture Day. It generally takes place under clear blue skies. The event features ground displays of various military aircraft from all three branches of theJapan Self-Defense Forces and a performance byBlue Impulse, the JASDF's aerobatics team. Police department helicopters are also usually on ground display.
A speaker at the 2010 air show sparked controversy when he criticized the government.[3][4]
Due to the base's proximity to Tokyo a large number of spectators attend the event each year, although numbers can fluctuate. In 2015 the attendance was approximately 200,000, in 2016 it was 130,000 and in 2017 around 210,000 people came to the event.[5]
As of 2017, the following units are based at Iruma:[6]