1912–1945: the Imperial Navy’s air arm, and how it ended

Japanese naval aviation is older than the Self-Defense Forces by four decades. The Imperial Navy set up a commission on aeronautical research in 1912, flew its first seaplanes at Oppama on Yokosuka Bay that year, and in September 1914 the seaplane carrier Wakamiya’s aircraft attacked German positions at Tsingtao, which Wikipedia calls the first naval-launched air raids in history. By 1941 the Imperial Japanese Navy Air Service was a carrier and land-based bomber force of the first rank; by 1945 it was sending young men from airfields such as Kanoya on suicide missions. Japanese Wikipedia counts 828 special-attack airmen who sortied from Kanoya alone in the Okinawa campaign. The service was dissolved with Japan’s defeat. Its story belongs in this page as background, not as lineage to be celebrated: the post-war maritime arm is a new organisation, though it took over many of the same airfields. The wars themselves are covered on the JASDF page.

1953–1961: starting again at Kanoya and Tateyama

The maritime air arm restarted under American tutelage and on a small scale. Japanese Wikipedia dates the first air unit at Kanoya to 1 December 1953, under the Maritime Safety Agency’s Safety Security Force, the body that became the Japan Maritime Self-Defense Force on 1 July 1954. The sources disagree on exactly when Kanoya passed to the navy: English Wikipedia gives 21 November 1955 for the full transfer. Tateyama, an Imperial Navy field on Tokyo Bay, was returned to Japan in 1953 and became the helicopter base. The first equipment came from the United States: Avenger hunter-killer groups in the 1950s and 1960s, and 60 S2F-1 Trackers delivered in 1957 from US stocks. The mission was set from the start and has never changed much: find submarines in the seas around Japan, and rescue people at sea.

1961–1989: Fleet Air Force, Neptunes, Trackers and flying boats

On 1 September 1961 the air units were gathered into the Fleet Air Force (Kōkū Shūdan) at Shimofusa, east of Tokyo; its headquarters moved to Atsugi in 1973. The 4th Air Wing formed in 1962 with nine P2V-7 Neptunes, and in October 1965 six of them flew to the Marianas to search for Japanese fishing boats caught by a typhoon, the first overseas mission by the fixed-wing force. Japanese industry soon took over: Kawasaki rebuilt the Neptune with turboprops as the P-2J (83 built, first flight July 1966), Mitsubishi built HSS-2 Sea King helicopters under licence, and ShinMaywa produced a home-designed flying boat, the PS-1 anti-submarine aircraft (21 built, in service from 1971) and the US-1 rescue amphibian (19 built, from 1975). The PS-1 had a short career and was retired in 1989; the US-1 became the service’s best-loved aircraft, credited by Wikipedia with 827 people rescued.

1983–2009: the Orion years and one night off Noto

The P-3C Orion set the shape of the force for the next forty years. The first P-3C squadron, the 6th at Shimofusa and later Atsugi, formed on 30 March 1983 with six aircraft, and Kawasaki went on to build more than 100 under licence, with electronic (EP-3), imagery (OP-3C) and test (UP-3C, UP-3D) variants. In 1991 the Mitsubishi-built SH-60J replaced the Sea King on destroyers; the SH-60K followed in 2005. A 1998 reorganisation cut the fixed-wing patrol squadrons from eight to four. The fleet had trained for the Soviet submarine threat, but its one real use of weapons came against North Korea. On the night of 23–24 March 1999, during Japan’s first maritime security operation, three P-3Cs from Hachinohe dropped 12 anti-submarine bombs as warning shots ahead of two spy ships off the Noto Peninsula. The ships escaped; nobody was hurt.

2009–2019: Djibouti, the P-1 and a radar dispute with Seoul

In 2009 the patrol force went abroad for a sustained operation for the first time. Two P-3Cs left for Djibouti on 28 May and began anti-piracy flights over the Gulf of Aden on 11 June, first from the US-run Camp Lemonnier and from 2011 from Japan’s own base beside the airport, its first long-term overseas base since 1945. At home the ShinMaywa US-2 replaced the US-1 from 2007, though only nine were built and one was written off in 2015. The Kawasaki P-1, a four-jet patrol aircraft designed in Japan, entered service on 26 March 2013; Atsugi’s 3rd Squadron became all-P-1 in August 2017. A year later the new aircraft was at the centre of a diplomatic row: Japan said a South Korean destroyer locked its fire-control radar on to a P-1 on 20 December 2018; Seoul denied it and accused the P-1 of flying dangerously low.

2019–2026: P-1 troubles, a fatal collision, drones and a carrier

The P-1 has not delivered the availability that was promised. Wikipedia reports that a July 2025 audit downgraded the fleet’s readiness to “poor” because of engine problems, avionics faults and a lack of spare parts, and the annual buy has fallen to two aircraft in FY2025 and one in FY2026. On 20 April 2024 two SH-60K helicopters collided during night anti-submarine training near Torishima, killing all eight crew; the rescue UH-60J was retired from the navy that July. The money is now moving towards unmanned aircraft, as the December 2022 Defense Buildup Program foreshadowed when it said P-1 numbers would be partially reviewed: the FY2026 budget buys four MQ-9B long-endurance drones for ¥76.5 billion, against three SH-60L helicopters and one P-1. Meanwhile the destroyer Kaga completed F-35B trials off California in November 2024. The jets will belong to the Air Self-Defense Force, not the navy; the navy’s own air arm remains a submarine-hunting and rescue force.