Japan Maritime Self-Defense Force aviation

The Japan Maritime Self-Defense Force (JMSDF) has a large aviation component. As of 2012, it was equipped with over 200 fixed-wing aircraft and 150 helicopters. These aircraft operate from bases throughout Japan, as well as from the JMSDF's ships.

History
The JMSDF's first aircraft were 16 Lockheed P2V Neptune – redesignated P-2 Neptune in the United States in September 1962 – maritime patrol aircraft, which were provided to the force by the United States Navy in 1956. The US Navy also provided Japan with 60 Grumman S-2 Trackers from 1957. During the 1980s, the JMSDFs force of 82 Neptunes (most of which were the locally built Kawasaki P-2J variant) was replaced by about 100 Lockheed P-3 Orions. The JMSDF's first combat helicopters were the Mitsubishi HSS-2 (the Japanese variant of the Sikorsky SH-3 Sea King). These helicopters were replaced by SH-60Js during the 1990s.

The JMSDF is the only force to operate minesweeping helicopters other than the US Navy. The first helicopters used for this purpose were eight V-107As. These helicopters were replaced by eleven MH-53Es during the 1990s. Seven MCH-101 helicopters have been ordered to replace the MH-53Es, of which five had been delivered by mid-2012.

Current organization
The organization of the JMSDF's aviation units is based on that of the US Navy. The main organizational units are Koku Shudan (air groups), Kokugan (air wings), Kokutai (air squadrons) and Hikotai (flights).

As at mid-2012, the structure of the JMSDF's aviation units was as follows:


 * 2nd Air Group (JMSDF Hachinohe Air Base)
 * 2nd Air Wing
 * 21 Air Squadron (P-3C Orion)
 * 32 Air Squadron (P-3C Orion)


 * 4th Air Group (Atsugi Air Base)
 * 3rd Air Wing
 * 31 Air Squadron (P-3C Orion)
 * 32 Air Squadron (P-3C Orion)
 * Atsugi Detachment (Shin Meiwa US-1A, ShinMaywa US-2)
 * 51st Air Wing
 * 511 Air Squadron (P-3C Orion, UP-3C Orion)
 * 513 Air Squadron (SH-60J, SH-60K, USH-60K)
 * Project Han (Kawasaki P-1)
 * 61st Air Wing (Beechcraft LC-90 King Air, NAMC YS-11M, YS-11MA)
 * 81st Air Wing (Lockheed EP-3, OP-3C Orion)
 * 91st Air Wing (Learjet U-36A, UP-3D Orion)
 * 111th Air Wing (MH-53E, CH-101, MCH-101)


 * 5th Air Group (Naha Air Base)
 * 5th Air Wing
 * 51 Air Squadron (P-3C Orion)
 * 52 Air Squadron (P-3C Orion)


 * 21st Air Group (JMSDF Tateyama Air Base)
 * 21st Air Wing (JMSDF Tateyama Air Base)
 * 211 Air Squadron (SH-60K)
 * 231 Air Squadron (SH-60J)
 * 23rd Air Wing (Maizuru Heliport)
 * 231 Air Squadron (SH-60J, SH-60K)
 * 25th Air Wing (Ōminato Air Field)
 * 251 Air Squadron (SH-60J)
 * 73rd Air Wing (Ōminato Air Field)
 * 73 Air Squadron (UH-60J)
 * Iwoto Flight (UH-60J, North Field, Iwo Jima)


 * 22nd Air Group (Ōmura Air Base)
 * 22nd Air Wing
 * 221 Air Squadron (SH-60K)
 * 222 Air Squadron (SH-60J, SH-60K)
 * 223 Air Squadron (SH-60J)
 * 24th Air Wing (Tokushima Airport)
 * 241 Air Squadron (SH-60J)
 * 72nd Air Wing
 * 72 Air Squadron (UH-60J)
 * Tokushima flight (UH-60J)
 * Kaonoya Flight (UH-60J, Kanoya Air Field)


 * 31st Air Group Iwakuni Air Base
 * 71st Air Wing (US-1A, US-2)

Units attached to destroyer fleets
 * Kure District Fleet
 * Komatsushima Air Squadron (SH-60J, Komatsushima Heliport)
 * Ōminato District Fleet
 * Ōminato Air Squadron (SH-60J, Ōminato airfield
 * Ōminato Flight (UH-60J)
 * Sasebo District Fleet
 * Ōmura Air Squadron (SH-60J, Ōmura Air Base)
 * Yokosuka District Fleet
 * Shirase Flight (SH-60J, JMSDF Tateyama Air Base)

Air Training Command
 * Shimofusa Air Training Group (Shimofusa Air Base)
 * 203 Air Training Squadron (P-3C)
 * 205 Air Training Squadron (no aircraft)
 * Tokushima Air Training Group (Tokushima Airport)
 * 202 Air Training Squadron (Beechcraft TC-90 King Air, Beechcraft UC-90 King Air)
 * Ozuki Air Training Group (Ozuki Air Field)
 * 201 Air Training Squadron (Fuji T-5)
 * 1st Air Group (Kanoya Air Field)
 * 1st Air Wing
 * 11 Air Squadron (P-3C Orion)
 * 12 Air Squadron (P-3C Orion)
 * 211 Air Training Squadron (OH-6D, OH-6DA, SH-60J, Eurocopter TH-135)