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MCAS Iwakuni
MCAS Iwakuni logo
MCAS Iwakuni logo
Airport type Military
Operator United States Marine Corps
Location Iwakuni, Yamaguchi, Japan
Built 1940
In use 1940 – present
Commander Col. James C. Stewart[1]
Occupants Marine Aircraft Group 12
Marine Aviation Logistics Squadron 12
Marine Wing Support Squadron 171
Elevation AMSL 10 ft / 3 m
Coordinates 34°08′42″N 132°14′39″E / 34.145°N 132.24417°E / 34.145; 132.24417Coordinates: 34°08′42″N 132°14′39″E / 34.145°N 132.24417°E / 34.145; 132.24417
RJOI is located in Japan
Airplane silhouette
Location in Japan
Direction Length Surface
m ft
02/20A 2,440 8,005 Concrete
Number Length Surface
m ft
02H/20H 365 1,198 Concrete
Sources: Official site[2]
Japanese AIP at AIS Japan[3]
Marine Corps Air Station Iwakuni - JMSDF Iwakuni Air Base (427022429)

Aerial photograph of MCAS Iwakuni.

Marine Corps Air Station Iwakuni or MCAS Iwakuni (IATA: IWK, ICAO: RJOI) is a United States Marine Corps air station located in the Nishiki river delta, 1.3 NM (2.4 km; 1.5 mi) southeast of the Iwakuni Station[3] in the city of Iwakuni, Yamaguchi, Japan.

Tenant commands[]

US Marine Corps[]

  • Marine Aircraft Group 12 (MAG-12) contains the rotary and fixed wing aircraft assets of Marine Corps Air Station Iwakuni. MAG-12 is home to four flying squadrons and a logistics Squadron.
  • VMFA(AW)-242 — only permanent Marine F/A-18 Hornet fighter squadron stationed abroad.
  • Marine Aviation Logistics Squadron 12 provides logistics support, guidance, and direction to MAG-12 and other commands aboard the Station. Click on the link to the right for more information on the Marauders.
  • 374th Airlift Wing 374th Communications Squadron provides communications support to H&HS, MAG-12, Branch Medical Clinic Iwakuni, Army Corps of Engineers, and JMSDF.

Japan Maritime Self-Defense Force[]

  • Fleet Air Wing 31 (第31航空群)[5]


The Japanese government bought a large portion of what is today MCAS Iwakuni in 1938, with the view of establishing a naval air station. They commissioned the new base 8 July 1940. When World War II started, the Iwakuni air station was used as a training and defense base. The station housed 96 trainers and 150 Zero fighter planes on the airstrip. In September 1943, a branch of the Etajima Naval Academy was established here, with approximately 1,000 cadets undergoing training in the Basic, Junior and Senior Officer's schools at any one time. American B-29's bombed Iwakuni in May and August 1945, concentrating on the oil refinery and Rail Transport Office or train station areas. The last air raid took place just a day before the war was brought to a close.

The first allies to reach Iwakuni at the war's end were a group of U.S. Marines who had signed papers ending the conflict for the Japanese air base. After the end of World War II, various military forces from the United States, Britain, Australia, and New Zealand occupied the base and it was repaired by No. 5 Airfield Construction Squadron RAAF. It was designated a Royal Australian Air Force Base in 1948. Then in 1952, the base officially became a United States military base.[6]

F-51Ds 77 Sqn RAAF at Iwakuni c1950

F-51Ds of RAAF No. 77 Squadron in maintenance at Iwakuni Airfield, June 1950.

The Americans first occupied the base in 1950 to use it as a springboard for aircraft heading to the Korean War.

It was revealed in 2010 that in 1966 nuclear weapons were moved to the base for storage from Okinawa. When U.S. ambassador to Japan Edwin O. Reischauer learned of the presence of the weapons, which was a violation of the Treaty of Mutual Cooperation and Security between the United States and Japan, he told the United States Department of State that if the weapons were not removed within 90 days he would resign and go public with the information. The weapons were removed shortly thereafter.[7]

On 14 July 1970, African-American soldiers and some anti-war soldiers raised a riot against the Vietnam War on the base.

It is currently home to around 5,000 United States Marines (including family members). The base is detailed for Marine pilot training and air patrol, using F/A-18 Hornet fighter-attack aircraft among others in compliance with the Treaty of Mutual Cooperation and Security obligations to protect Japan. MCAS Iwakuni is also shared with the Japanese Maritime Self Defense Force. MCAS Iwakuni has an air station that many people in Iwakuni want to be made into a public international airport. MCAS Iwakuni is home to a Department of Defense school, Matthew C. Perry (Elementary and High School).

In 2014, it is planned to move the U.S. Carrier Air Wing from Atsugi to Iwakuni which will further increase the size of the base.[8] However, due to construction delays, the Navy will continue to operate out of NAF Atsugi until 2017.[9]

The USMC's aircraft procurement plan for fiscal year 2010 revealed that the Corps plans to station 16 F-35B aircraft at Iwakuni beginning in the fall of 2015 to replace the AV-8 and F/A-18 aircraft currently stationed at the base. The F-35B's engines are louder than those of the AV-8 and F/A-18 which may have an impact on the local community.[10]

A new off-shore runway opened at the base on 30 May 2010. The new runway is 2,440 meters in length.[11]

Since 2000, the base has killed approximately 25,000 Black Widow spiders which apparently came to the base in cargo and luggage of Americans assigned to the base. The spiders are not native to Japan, so local American and Japanese authorities are attempting to keep them from spreading beyond the base. 203 of the spiders were found and killed between October 2009 and January 2010.[12]

F-18 Iwakuni

USMC F/A-18D takes off from MCAS Iwakuni in December 2005

Commercial Services[]

Regular commercial service started from December 13, 2012 with a civilian airport terminal built to accommodate commercial flights. It was initially projected that up to 430,000 passengers would use the airport each year,[13] and in the first seven months of operations the airport handled over 200,000 passengers, with average load factors between Iwakuni and Tokyo exceeding 70% during June 2013.[14] Since IATA airport code IWJ, formerly assigned to Iwakuni, was already reassigned to Iwami Airport, new IATA code of IWK was assigned to Iwakuni. The inaugural flight was operated by All Nippon Airways from Haneda Airport. Also, Iwakuni Airport will be called by its official nickname "Iwakuni Kintaikyo Airport", named after the Kintaikyo bridge near the airport.


Airlines Destinations 
All Nippon Airways Tokyo-Haneda

Friendship Day[]


Air show at MCAS Iwakuni during Friendship Day 2008.

Every year on 5 May, Japanese Nationals and U.S. service members, government employees and their families officially celebrate their long-standing friendship by opening the gates of MCAS Iwakuni for one of Japan's largest air shows dedicated to enhancing the friendship of the two nations. The event, entitled Friendship Day, hosts an average 250,000 visitors who travel from all over Japan.[15][16]

See also[]


This article incorporates text in the public domain from the United States Marine Corps.

PD-icon This article incorporates public domain material from the Air Force Historical Research Agency website

  1. James C. Stewart
  2. MCAS Iwakuni, official website. Retrieved 17 March 2010
  3. 3.0 3.1 AIS Japan
  4. Headquarters and Headquarters Squadron
  5. Air Station Iwakuni - Unit (Japanese)
  6. MCAS Iwakuni, Japan. (n.d.). MCAS Iwakuni History. Retrieved 17 March 2010,
  7. Jiji Press/Kyodo News, "U.S. kept nuclear arms at Iwakuni in 1966: scholar", Japan Times, 17 March 2010, p. 1.
  8. Dae-woong, J. (2006, 15 September). The Korea Herald. Retrieved 11 January 2009, from Lexis Nexis Academic database.
  9. Burke, Matthew M. and Hana Kusumoto,"Air Wing's Move from Atsugi Delayed 3 Years", Stars & Stripes, 25 January 2013.
  10. Shimbun Akahata, "F-35B to be deployed to Iwakuni", 22 October 2009.
  11. Japan Times, "New Offshore Runway at U.S. Iwakuni Operational", 30 May 2010.
  12. Burke, Matthew M., and Elena Sugiyama, "Iwakuni battles to keep black widow spiders confined to base", Stars & Stripes, 7 June 2011.
  13. Japan carrier to offer Iwakuni flights
  14. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "開港半年の岩国空港、利用は堅調". 日本経済新聞. Retrieved 5 August 2013. 
  15. {{cite press release BUT, in the year 2011, they decided to cancel Friendship Day (just for that year) because of the typhoon & tsunami up north. They thought it was sending a message that we were celebrating the tragedy. In my opinion, it would be best if we had still had Friendship Day (and added some type a booth to raise money for the people up north) because it would send a message that we want to extend our friendship towards the Japanese on this day and help them with what they were, and still are, going through. |accessdate=10 June 2008 |url= |title=Press Conference for 2008 Friendship Day |date=8 April 2008 |publisher=MCAS Iwakuni, United States Marine Corps }}
  16. Republic of Égyptien Q42 user:mgbtrust0 ®™✓©§∆∆∆€¢£. "Friendship Day website" (in Japanese). 

External links[]

All or a portion of this article consists of text from Wikipedia, and is therefore Creative Commons Licensed under GFDL.
The original article can be found at Marine Corps Air Station Iwakuni and the edit history here.