The State of Japan / Nippon-Koku/Nihon-Koku

Brief history
Welcome to the Japan pages of Scramble. On this landing page you will find links to the three Self-Defense Forces. Because of the size of the forces, every air arm has its own page, providing you with information on its history and serial system. Furthermore, besides the three major forces, we also have one page on pre-1954 aviation units, so government agencies with aviation assets before the conception of the three forces, and one page on the Japan Coast Guard. Of course you will find links to the Order of Battles for the Self-Defense Forces and the Coast Guard, and maybe most importantly to the Database. The first info page, providing you with information on past units, their location, insignia and equipment of the JASDF is now on-line. It is in the well known OrBat form, so for each airfield per timeframe, following mainly the changes in Hikotai history. Most historic informaton was gathered from the excellent publication 'JAPANESE AIR ARMS 1952-1984' by Akira Watanabe.

On this page we have collected some information on Japan and its difficult administrative division into Prefectures, sub-Prefectures etc. This is especially relevant for the serious Wrecks and Relics collector as the location indicator in the Japan database for preserved aircraft is following this system.

Article 9 of the Japanese Constitution
"Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes. To accomplish this aim, land, sea and air forces, as well as other war potential will never be maintained".

Japan General Information
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters that make up Japan's name mean "sun-origin", which is why Japan is sometimes referred to as the "Land of the Rising Sun". Japan is an archipelago of 6,852 islands. The four largest islands are Honshu, Hokkaido, Kyushu, and Shikoku, which together comprise about ninety-seven percent of Japan's land area. Japan has the world's tenth-largest population, with over 127 million people. Honshū's Greater Tokyo Area, which includes the de facto capital city of Tokyo and several surrounding prefectures, is the largest metropolitan area in the world, with over 30 million residents. Archaeological research indicates that people lived in Japan as early as the Upper Paleolithic period. The first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other nations followed by long periods of isolation has characterized Japan's history. From the 12th century until 1868, Japan was ruled by successive feudal military dictatorships (shogunates) in the name of the Emperor. Japan entered into a long period of isolation in the early 17th century, which was only ended in 1853 when a United States fleet pressured Japan to open to the West. Nearly two decades of internal conflict and insurrection followed before the Meiji Emperor was restored as head of state in 1868 and the Empire of Japan was proclaimed, with the Emperor as a divine symbol of the nation. In the late 19th and early 20th centuries, victory in the First Sino-Japanese War, the Russo-Japanese War and World War I allowed Japan to expand its empire during a period of increasing militarism. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the atomic bombings of Hiroshima and Nagasaki. Since adopting its revised constitution in 1947, Japan has maintained a unitary constitutional monarchy with an emperor and an elected legislature called the Diet.

Administrative divisions
Japan consists of forty-seven prefectures, each overseen by an elected governor, legislature and administrative bureaucracy. The nation is currently undergoing administrative reorganization by merging many of the cities, towns and villages with each other. This process will reduce the number of sub-prefecture administrative regions and is expected to cut administrative costs.

The prefectures of Japan are the country's 47 first-order subnational jurisdictions on a state or provincial level. Prefectures are governmental bodies larger than cities, towns, and villages. The former provinces of Japan were converted into prefectures in the 1870s. Under the current Local Autonomy Law, each prefecture is further subdivided into cities (市, shi) and districts (郡, gun). Each district is further subdivided into towns (町, chō/machi) and villages (村, son/mura). There are several types of prefecture:

  • One "metropolis" (都, to), Tokyo; Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture (Tōkyō-fu) and the city of Tokyo (Tōkyō-shi) and now has in its bounderies 23 special wards (tokubetsu-ku) e.g. Nerima-ku, 26 cities, e.g. Fushu-shi, one district and two island chains in the Pacific Ocean directly south which stretch more than 1,000 km away from the mainland.
  • One "circuit"/territory (道, ), Hokkaido; Hokkaido has 14 subprefectures(支庁, shichō) which act as branch offices of the prefecture.
  • Two urban prefectures (府, fu), Osaka and Kyoto
  • 43 other prefectures (県, ken).

The prefectures are often grouped into nine regions (Chihō). The regions of Japan are not official administrative units, but have been traditionally used as the regional division of Japan in a number of contexts. For instance, maps and geography textbooks divide Japan into the eight regions, weather reports usually give the weather by region, and many businesses and institutions use their home region as part of their name (Kinki Nippon Railway, Chūgoku Bank, Tōhoku University etc.) From north to south the prefectures of Japan and their commonly associated regions are:

Hokkaido (largest city Sapporo)

1. Hokkaido

Tōhoku (largest city Sendai)

2. Aomori
3. Iwate
4. Miyagi
5. Akita
6. Yamagata
7. Fukushima

Kantō (largest city Tokyo)

8. Ibaraki
9. Tochigi
10. Gunma
11. Saitama
12. Chiba
13. Tōkyō
14. Kanagawa

Chūbu, sometimes divided into Hokuriku, Koshin'etsu and Tokai regions. (largest city Nagoya)

15. Niigata
16. Toyama
17. Ishikawa
18. Fukui
19. Yamanashi
20. Nagano
21. Gifu
22. Shizuoka
23. Aichi

Kansai (largest city Osaka)

24. Mie
25. Shiga
26. Kyōto
27. Ōsaka
28. Hyōgo
29. Nara
30. Wakayama

Chūgoku (largest city Hiroshima)

31. Tottori
32. Shimane
33. Okayama
34. Hiroshima
35. Yamaguchi

Shikoku (largest city Matsuyama)

36. Tokushima
37. Kagawa
38. Ehime
39. Kōchi

Kyushu (largest city Fukuoka)

40. Fukuoka
41. Saga
42. Nagasaki
43. Kumamoto
44. Ōita
45. Miyazaki
46. Kagoshima


47. Okinawa

Source www.wikipedia.org

Hoantai & Keibitai

Article 9 of the Japanese Constitution
"Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes. To accomplish this aim, land, sea and air forces, as well as other war potential will never be maintained".

Keisatsu Yobitai and Kaijyo Keibitai
After the unconditional Japanese surrender in 1945, Japan was occupied and controlled by allied, mostly United States forces and thoroughly de-militarised. Its pre-war society was mainly controlled by the military and therefore deemed potentially dangerous, so all traces of militarism had to be eliminated, including a ban on all flying. This is also stated in the Japanese constitution which forbids Japan to set up and maintain armed forces with war potential. Even to this day, officially the Japanese Self-Defense Force is a policing force and all JSDF personnel are civilians, being special civil servants. So post war military security was provided by the allies under command of US general MacArthur. This lasted until the start of the Korean War in 1950 when the bulk of the allied occupation force was sent to fight in Korea, leaving Japan undefended. The US Government now openly admitted it needed a partly rearmed Japan, basically to defend itself but also as a regional ally against the Communist threath. To by-pass both the now anti-military feelings in society and the article in the constitution, the Keisatsu Yobitai (National Police Reserve) was established on 10th August 1950. The role of this 75.000 strong para-military organisation was to maintain law and order in the home islands, but between the lines also to provide the defence against agressors. It was equipped with surplus US military hardware. A maritime force was formed on 26 april 1952, the Kaiyo Keibitai (Maritime Guard).

Photo: Scramble

In August 1952, Japan was allowed to set up a Hoancho (National Safety Agency) which gained control of all Japanese para-military forces. The Keisatsu Yobitai was reorganized and renamed into Hoantai (National Safety Force), the Kaijyo Keibitai was reorganized and renamed into the Keibitai (Coastal Safety Force). It was the Hoantai which received the first post-war aircraft in October 1952 when twenty Aeronca L-16s were supplied for training purposes.

15 October 1952 marked the start of post WW2 military aviation in Japan as the Hoantai received twenty Aeronca L-16s from US stocks. They were used for training by the Koku Gakko (Aviation School) at Hamamatsu, a former wartime operational training base. These were returned to the USA with the arrival of 35 Stinson L-5s, first examples delivered in January 1953. Further deliveries included 62 Piper L-21Bs, ten Beechcraft T-34s, six Bell H-13Es and some Cessna L-19As. A number of aviation units were activated in January 1954 and these included 1st and 3rd Kokutai (Aviation Corps) at Hamamatsu, 2nd Kokutai at Asahikawa, 4th Kokutai at Ozuki and Hokubu Homen Kokutai (Northern Army Avtn Corps) and Tokkadan Kokutai (Artillery Brigade Avtn Corps) at Okadama. All aircraft had a unique Hoantai number applied to both sides of the fuselage or fin (some in the H-xxxx format), while retaining their original US serial on the rear fuselage or fin.

The Keibitai received its first aircraft on 16 September 1953. Tateyama Kokutai was formed, equiped with four Bell 47D-1 helicopters. A fixed-wing training unit was formed at Kanoya, the Kanoya Kokutai, and received ten Beechcraft T-34As. Further equipment came in the form of three Sikorsky S-55s and three Westland WS-51 Mk.1As. All Keibitai aircraft received a two-part serial number, painted on the vertical tail. The serial numbers were composed of a prefix in Japanese characters, indicating the Kokutai, and a three digit number. The prefix was an abbreviation of the unit name in two Japanese characters, Tateyama Kokutai becoming TATEKU and Kanoya Kokutai KANOKU.

Photo: Scramble

In 1954 the parliament approved the Self-Defence Law and therefore the Hoancho was replaced by the Boeicho (Defence Agency) which was formed to control the three military services we still know today. The Hoantai was reorganised into the Rikujo Jieitai (Japanese Ground Self-Defense Force). Except for the T-34 Mentors which were handed over to the newly formed JASDF, all the Hoantai's aviation assets were retained by the Rikujo Jieitai and were reserialled. The Keibitai was reformed and renamed into the Kaijo Jietai (Japanese Maritime Self-Defense Force) and on 1st July 1954, all its assets were taken on JMSDF charge and reserialled.

Source Japanese Air Arms 1952-1984 by Akira Watanabe

Nihon Kōkū Jieitai - 航空自衛隊

In 1954 the parliament approved the Self-Defence Law and therefore the Hoancho was replaced by the Boeicho (Defence Agency) which was formed to control the three military services we still know today. The two other Self-Defense Forces were re-organized existing organisations (see pre-1954 aviation units), however the Nihon Koku Jietai (Japanese Air Self-Defense Force) was newly established on 1st July 1954, making it the country's first independent air arm. Its first equipment ten Beechcraft T-34A Mentors acquired from the old Hoantai, forming the core of the nowadays Nihon Koku Jietai.

The large need for pilots and support personnel resulted in the establishment of a Sojyu Gakko (Flying School) on 6th July 1954, based at Hamamatsu airbase, equipped with the ten Beechcraft T-34A Mentors. This type was selected as the force's standard primary trainer, and the original ten were later supplemented with 124 additional aircraft licence built by Fuji Heavy Industries. In 1955 the NKJ received its first aircraft out of American stocks. These aircraft comprised numbers of North American T-6 Texans, acting as the standard advanced trainer and in anticipation of jet fighters, Lockheed T-33s as the standard jet trainer. All these training aircraft equiped seven Hiko Kyoikudans (Flying Training Wings). Curtis C-46 Commandos were received and a modest transport fleet was set up, initially at Tachikawa before moving to Miho as the Yuso Kokudan (Air Transport Wing). The first fighters were delivered in December 1955 when a number of F-86F Sabre fighters arrived in Japan. The delivery of these F-86s coincided with the establishment of the Kokudan (Air Wing) at Hamamatsu airbase, eventually forming the 1st and 2nd Hikotai (Squadron) within it, both equipped with F-86F Sabres. As more types were entering the inventory, an operational test and evaluation unit was also activated at Hamamatsu in December 1955, the Jikken Kokutai (Air Proving Group). At the end of 1956 the air force had 96 T-34 Mentors, 130 T-6 Texans, 68 T-33 T-birds, 8 F-86F Sabres and 24 C-46 Commandos on strength as well as one Kawasaki KAL-2 being the first post WW2 Japanese designed aircraft. The F-86F Sabre was to become the primary JASDF fighter and was also built by Mitsubishi, first examples completed in Japan were delivered September 1956. As the number of Sabres increased, more Kokudans were activated and the original Kokudan became 1st Kokudan, still acting as a conversion training unit. 2nd Kokudan was formed at Hamamatsu in October 1956 with a single F-86F squadron, the 3rd Hikotai. First JASDF rotary equipment was the Sikorsky H-19, first examples arrived in 1957 and these became part of Rinji Kyunan Kokutai (Provisional Air Rescue Squadron) in March 1958, together with T-6 and T-34 aircraft. The F-86D Sabre all-weather fighter was introduced January 1958, ultimately forming four Hikotais in 3rd Kokudan. The Hiko Tenkentai (Flight Check Group) was formed October 1958, equiped with modified C-46 Commandos. The contours of the JASDF we know today were becoming very visible.

Photo: Scramble

During the second half of the nineteen fifties and early nineteen sixties, the NKJ expanded to a sizeable air force with the backbone being formed by 180 US built and 300 Mitsubishi built F-86Fs. These, together with F-86D all weather interceptors formed six Kokudans in the Koku Sotai (Air Defence Command) and one Kokudan in Hiko Kyoiku Shudan (Flying Training Command). Initial numbering of the fighter Hikotais was fairly straightforward as every type had its own sequence. Numbers 1 to 10 Hikotai were F-86F squadrons, 101 to 105 Hikotai were F-86D squadrons. With the introduction of new types into service, a new sequence was started and old units were simply disbanded. One of the elements still missing, a tactical reconnaissance unit was established December 1961 when 501 Hikotai was activated at Matsushima, flying converted Sabres designated RF-86F. During the beginning of the nineteen sixties the fleet of T-6 Texans was gradually being replaced by the locally developed Fuji T-1. The Kyunan Kokutai (Air Rescue Squadron) expanded considerably with deliveries of new helicopters, H-21Bs arriving in 1960 and Mitsubishi built S-62Js in 1963 and was upgraded to group status, becoming the Koku Kyunangun. In 1962 a new era started for the NKJ when the Lockheed F-104J Starfighter was selected as the successor to the F-86 Sabre in the air defence role. Between 1962 and 1967 210 Mitsubishi F-104J and 20 F-104DJ Starfighters were delivered equipping seven squadrons, 201 to 207 Hikotai. Surplus F-86F Sabres formed yet another Kokudan and two new Kokutais, so when the last F-104J Hikotai was formed in 1966, the NKJ had eighteen Hikotais in the Koku Sotai. An ECM Training Flight, the Denshi Kunrentai was formed at Kisarazu in 1964, part of Koku Sotai Shireibu Hikotai (HQ Squadron) and it operated a few converted C-46 Commandos. During the end of the sixties the first Kawasaki KV-107s were taken on charge as a replacement for the H-19 and H-21 and also entering service around that time was the Mitsubishi MU-2, replacing the last T-6s and T-34s in rescue service. Already the JASDF was thinking about a successor to the Starfighter and in 1968, the McDonnell F-4E was selected.

Photo: Scramble

July 1971 saw the start of F-4EJ deliveries, the type ultimately equipping six squadrons, 301 to 306 Hikotai. The seventies also saw the development and introduction of a number of indigenous aircraft types, of which only the Kawasaki C-1, which succeeded the ageing fleet of C-46 Commandos, and the NAMC YS-11 still can be seen on the inventory today. The Mitsubishi T-2 replaced the last F-86Fs in the advanced training role, two squadrons were activated, 21 and 22 Hikotai. RF-4EJs replaced the RF-86F in 501 Hikotai service, last recce Sabres leaving the unit in 1977. That same year saw the first flight of the first Mitsubishi designed fighter, the F-1, and this T-2 variant replaced the last F-86F Sabres in the tactical fighter role. The practise of starting a new sequence with the introduction of a new type was discontinued with the introduction of this aircraft, former Sabre units 3, 6 and 8 Hikotai retained their unit number. The Fuji T-3 replaced the T-34 in the primary training role and re-equipped 11 and 12 Hiko Kyoikudan. In 1977 the F-15J was already selected as the successor to the F-4EJ fleet for which deliveries were not even completed by that time!

Photo: Scramble

Eighties to present
During the first half of the nineteen eighties the NKJ retired the last C-46s, T-34s and F-86s and deliveries of the F-15J started in earnest. First Hikotai re-equipped with the Eagle was 202 Hikotai at Nyutabaru in December 1981, followed by 203 Hikotai at Chitose and 204 Hikotai at Nyutabaru, all units previously F-104 operators. One of the last elements still missing, an aggressor squadron, was activated December 1981 at Tsuiki and used five Mitsubishi T-2s. Hiko Kyodotai moved to its current base Nyutabaru in March 1983. Also activated in this decade was the Rinji Keikai Kokutai (Provisional Airborne Early Warning Group) with one squadron, 601 Hikotai operating the E-2 Hawkeye from Misawa. The C-130 Hercules was ordered to supplement the Kawasaki C-1 and re-equipped 401 Hikotai, its C-1s being transferred to the other units. A big advantage of the C-130 over the C-1 is its ability to fly fully loaded from the Tokyo region to Okinawa non-stop, where as the C-1 needs a fuel-stop at Tsuiki or Nyuatabaru. The nineties and first part of the new decade saw the retirement of the fleet of T-33s and T-1s by Kawasaki T-4s, the KV 107 by the UH-60J and CH-47J, the Mu-2 by the U-125, the Beech 65 by the U-4 Gulfstream, the T-3 by the T-7 and the Mitsubishi F-1 and T-2 by the Mitsubishi F-2. One of the last units newly established was 701 Hikotai, the dedicated VIP transport squadron operating the Boeing 747-400. These aircraft were untill recently the only ones seen abroad on a regular basis but Japan is now progressively more active outside its own borders, helping out on disaster relief flights and also joining multi-nation exercises such as Cope Thunder. Therefore Japan introduced tanker aircraft in the form of KC-767s (404 Hikotai) and also modifying C-130s into the tanker role. All future UH-60Js will have air to air refuelling capabilities. Mid 2012, Japan decided on the successor of the remaining F-4EJs and chose the Lockheed-Martin F-35, to be licence built by Mitsubishi. Future F-35 base will be Misawa.

Photo: Scramble

Serial Number System
JASDF serial numbers are made up of six digits, a two-digit prefix followed by a four-digit number. Besides denoting a particular aircraft, it also gives its type, role and year of procurement.

The first digit of the prefix indicates the year (Western calendar) it was delivered, for example F-2A 13-8508 was delivered in 2001. (This particular aircraft made its first flight in 2000 and was also supposed to be delivered in that year, so serial 03-8508 was applied, however testing took longer then anticipated and delivery slipped into the new year and it was subsequently re-serialled as 13-8508).

The second digit of the prefix denotes the type, allocated within four basic categories, as follows:

  Prop single-engine Prop multi-engine Jet Helicopter
1 T-34, T-3 C-46 T-33, T-400 H-19
2 T-6 YS-11 F-86F, F-15, U-125A H-21
3 T-28 B-65, MU-2 Vampire, F-2 S-62
4   E-2 F-86D, EC-767 KV-107
5   C-130 T-1, U-4  
6 T-7   F-104, T-4  
7     F-4, KC-767 CH-47
8     C-1, C-2 UH-60
9     T-2, U-125, F-35A  
0 KAL-2   F-1, B747, B777  

The first digit of the four-digit number indicates the basic aircraft role, as follows:

  Basic aircraft configuration
0 Piston-engined trainer
1 Transport
2 not used
3 Other prop/jet aircraft
4 Helicopters
5 Turboprop and jet trainer
6 Reconnaissance jet
7 Day jet fighter
8 All-weather fighter
9 not used

The final three digits are the aircraft's individual number. So, serial 48-1004 allocated to a C-1 can be decoded as:

  • 4 - year digit for year of delivery 1974
  • 8 - type digit for Jet
  • 1 - role digit for Transport
  • 004 - 4th C-1 in JASDF service

Source Japanese Air Arms 1952-1984 by Akira Watanabe

Rikujō Jieitai - 陸上自衛隊

In 1954, the Self-Defence Law was approved andthe Hoancho was replaced by a Boeicho (Defence Agency) and the Hoantai (see pre-1954 aviation units) was reorganised and renamed into the Rikujo Jieitai (Japanese Ground Self-Defense Force). All the aviation units of the Hoantai were integrated into the JGSDF and except for the T-34 Mentors, which were handed over to the newly formed JASDF, all the Hoantai's aviation assets were retained by the Rikujo Jieitai.

The Rikujo Jieitai was formed on 1st July 1954 and it inherited all units and equipment of the Hoantai. Its air component was intended as an integral part of the ground forces, tasked with observation, communications and casualty evacuation. In addition to the former Hoantai aircraft, it received a total of 31 Sikorsky H-19s and 94 Bell H-13s, entering service from 1954 onwards. Additional fixed wing aircraft were received, such as the L-19 (129), L-21 (62) and Fuji LM-1 (27). During the early years, the original six Kokutais (Aviation Corps) were carefully expanded so at the beginning of the sixties, the Rikujo Jieitai comprised of about twelve Kokutais and the Koku Gakko. On March 1959, the 1st Herikoputatai (Helicopter Squadron) was activated at Akeno, as part of Koku Gakko. At the end of the same month it moved to Kasumigaura with its complement of Sikorsky H-19 and Vertol V44 helicopters.

Photo: Scramble

In January 1962 a major reorganisation took place. The Kokutais were renamed Hikotais (Aviation Squadron) and these were grouped in Kokutais attached to five separate army field forces. These armies were named geographically as follows: Hokubu Homentai (Northern Army), Tohoku Homentai (Northeastern), Tobu Homentai (Eastern), Chubu Homentai (Central) and Seibu Homentai (Western). The Kokutais falling under an army also used the geographic name, e.g. Hokubu Homen Kokutai (Northern Army Avtn Group). Each Kokutai controlled several Hikotais: one Homen Hikotai (also using the geographic name), acting as the HQ flight of the regional army and several numbered Hikotais which belonged to Divisions with the same number. This basic structure stands to the present day. The Homen Hikotais operated mainly the L-19, L-21 and LM-1, where as the numbered Hikotais mainly used L-19, L-21 and H-13. Modern equipment came in the form of UH-1B helicopters, built by Fuji, deliveries started in 1962. Halfway the sixties, the L-21 was retired. Beginning 1968 saw a major expansion of helicopter operations. The 1st Herikoputatai was re-organised as the 1st Herikoputadan (Helicopter Brigade), it became an independent unit with 1st and 2nd Herikoputatai formed within and both squadrons moved to Kisarazu. These units became the main user of the Kawasaki-Vertol KV-107, first examples delivered 1966. A total of seventy KV107s were delivered, becoming the medium transport helicopter in the service. Also the regional Kokutais expanded, a Homen Herikoputatai was newly formed within each one, operating the UH-1B for light transport duties.

A modest modernisation took place in this decade. The Homen Hikotais received the OH-6J and Mitsubishi LR-1 as a replacement for their L-19 and LM-1, which were retired by the end of the 1970s. The Homen Herikoputatais retired the H-19 and these and the oldest UH-1Bs were replaced by the UH-1H, deliveries of the Bell UH-1H commenced in 1973. The majority of H-13s was also phased out during the 1970s and its main user, the numbered Hikotais received the OH-6J and UH-1B. With the return of control over Okinawa, the 1st Konseidan was activated at Kumamoto, moving to Naha in November 1972. Its aviation element was renamed 101 Hikotai in 1973, operating KV-107, UH-1B, LM-1 and LR-1, all painted in a beautiful white/orange/black colour scheme.

Photo: Scramble

Eighties to present
A major modernisation of the rotary aircraft fleet took place during the 1980s and 1990s with the OH-6J being replaced by the OH-6D of which 193 were delivered, the UH-1B and a part of the UH-1H fleet by the UH-1J, production finally stopped in 2012, and the UH-60JA. The KV107 was replaced by the CH-47J and CH-47JA, still under production by Kawasaki. The AH-1S entered service as the JGSDF tactical support helicopter in 1979 and 94 have been delivered since. The Raytheon LR-2 is now very slowly replacing the sole remaining fixed wing aircraft, the Mitsubishi LR-1. An indigenous helicopter type which entered service is the Kawasaki OH-1, replacing OH-6Ds with the Anti-tank units. A replacement programme for the AH-1S Cobra, the AH-X programme, was won by the AH-64D, however budget constraints only allow acquisition of a small number of these helicopters, built by Fuji HI, to replace the Cobras of one Anti-tank unit (3rd ATH at Metabaru). It is possible Kawasaki HI will develop an armed version of the OH-1. Latest helicopter now entering service is the Enstrom TH-480, replacing the OH-6D in the training role.

A Homen Kokutai typically consists of a Homen Kokutai Honbuzukitai (Army Air Group Headquarters Squadron) with LR-2, a Homen Herikoputatai (Army Helicoptersquadron) equipped with UH-1/UH-60 and OH-6 helicopters as well as a Taisensha Herikoputatai (Anti-Tank helicopter squadron) equipped with AH-1S/AH-64 and OH-1. In addition each assigned Shidan (Division) or Ryodan (Brigade) has it's own liaison squadron equipped with UH-1J and OH-6D. The numbering of these Hikotai's reflects the division/brigade to which it is assigned. The bulk of the Rikujo Jieitai's heavy airlift power is based at Kisarazu, where a Yuso Herikoputagun (Helicopter Transport Wing) is based consisting of four hikotais with CH-47J/JA Chinooks.

Serial Number System
JGSDF aircraft are identified by a five-digit serial number on both sides of the forward fuselage and in abreviated form (last four digits only), prefixed JG-, on the vertical tail. The first digit of the full serial indicates the aircraft's primary role, as follows:

  Primary role
1 fixed-wing liaison/observation
2 fixed-wing miscellaneous
3 helicopter, observation
4 helicopter, light transport
5 helicopter, medium transport
6 trainer
7 helicopter, tactical support
8 trainer
9 not used
0 helicopter, VIP transport

Source Japanese Air Arms 1952-1984 by Akira Watanabe

Kaijō Jieitai - 海上自衛隊

In 1954, the Self-Defence Law was approved and the Hoancho was replaced by a Boeicho (Defence Agency) and the Keibitai (see pre-1954 aviation units) was reorganised and renamed into the Kaijo Jietai (Japanese Maritime Self-Defense Force) and on 1st July 1954, all its assets were taken on JMSDF charge and reserialled.

Initially, all new equipment (but one, a single Kawasaki KAL-2) of the Kaijo Jietai were surplus US Navy aircraft and numbers of North American SNJs and Grumman TBM-3W2 and TBM-3S2 Avengers were delivered to Japan for training purposes. Lockheed PV-2 Harpoons were also delivered and formed a PV-2 patrol unit in September 1955 and were later also used for training. Newly activated Ominato Kokutai received the three Westland WS-51 helicopters in May 1956 and was an operational helicopter unit. Bigger, more modern and complex aircraft came in the form of 16 Lockheed P2V-7 Neptunes, later augmented by 48 Kawasaki built examples, for maritime patrol and 60 Grumman S2F-1 Trackers for ASW. Early 1960, the Neptunes and Trackers formed six Hikotais within three Kokutais (Hachinohe, Kanoya and Tokushima Kokutai) and to train these crews, 35 Beechcraft SNB Expediters, first received in 1957, were used by the Iwakuni Kyoiku Kokutai. ASW helicopter operations commenced in 1958 with the delivery of eight HSS-1 and nine HSS-1N Sea Bat helicopters, forming 101 Hikotai within the Tateyama Kokutai. Other early equipment were small numbers of the Grumman JRF Goose and Consolidated PBY Catalina, operated by Omura Kokutai, which by 1961 were replaced by the Grumman UF-2 and Douglas R4D aircraft operating from Kanoya. So by early 1960, the JMSDF had seven Air Stations, eight Kokutais divided into multiple Hikotais.

Photo: Scramble

A major reorganisation took place in 1961 and the structure as it was set up in September of that year, is still active today. All base Kokutais were disbanded and replaced by Kokuguns (Fleet Air Wing) and these could contain up to three Kokutais (basically the old Hikotais). The Kokuguns came under control of the Koku Shudan (Fleet Air Group/Command) which also controlled some independent Kokutais. All training Kokutais received numbers and fell under the Kyoiku Koku Shudan (Air Training Command). To identify the unit, the Kokutai number or the air station Kana character was painted on the vertical tail. Initially four Kokuguns were formed (1st, 2nd, 3rd and 21st Kokugun), but in September 1962 the 4th Kokugun was activated at Shimofusa for ASW duties. That same year began the replacement of the SNJ by Fuji KM-2s and a year later the replacement of the SNB by Beech 65 Queen Airs. In the nineteen-sixties, helicopter operations intensified enormously and the first serie of rotory equipment changes began. 55 HSS-2, 28 HSS-2A and 84 HSS-2B Sea Kings were built by Mitsubishi between 1964 and 1987 and these supplemented and replaced the older types in use. Another type acquired by the JMSDF was the Kawasaki Vertol 107 of which nine were operated in the minesweeping role between 1963 and 1988. A less significant type was the Sikorsky S-62, which began replacing the S-55 from 1965 onwards and was the prime rescue helicopter during the seventies and eighties. Also for the JMSDF, the local aircraft industrie became a major player this decade. The locally developed turbo-prop powered P-2J, built by Kawasaki first flew in 1966 and entered quantity production at the end of the decade, set to replace the P2V-7. The NAMC YS-11 started to replace the aging R4D with 205 Kyoiku Kokutai and off course the Shin Maywa flying boat made a first flight in October 1967. In the early 1960s Shin Maywa industries started development work for a project designated as the PS-X, the result was the Shin Maywa PS-1 and the two prototypes were handed over to 51 Kokutai at Iwakuni for tests.

The original P2V-7 and Trackers were being gradually replaced by the P-2J, last examples retired in 1982 while the last Tracker left in 1983. The OH-6 replaced the Bell 47 in the helicopter training role with 211 Kyoiku Kokutai, the Beechcraft King Air (TC-90) supplemented and later replaced the Queen Air with 202 Kyoiku Kokutai 31st Kokugun with 31st Kokutai was activated in March 1973, operating 23 PS-1s from 1973 till 1987. The SAR version, the Shin Maywa US-1(A) replaced the UF-2 from 1976 onwards, serving newly activated 71 Kokutai. Twenty were built and it is still in use and still in limited production, albeit as the US-2. At the end of the decade, the Lockheed P-3 Orion was selected as the replacement for the Kawasaki P-2J.

Photo: Scramble

Eighties to present
Equipment introduced in the seventies and eighties is still largely flying today, although with some types the oldest examples were replaced by new built ones. The Lockheed P-3C Orion replaced the P-2J and PS-1, first examples delivered in April 1981, first operational Orion unit was newly activated 6 Kokutai (within 4th Kokugun) at Atsugi. At one time, nine operational Kokutais operated the Orion, being 1 to 9 Kokutai and more were serving training unit 203 Kyoiku Kokutai and test unit 51 Kokutai. A few P-2Js were modified to UP-2J and served 81 Kokutai for special support duties. These were later also replaced by special Orions. The Sikorsky H-60 replaced the HSS-2 and S-62, the Fuji T-5 the KM-2 and the Sikorsky MH-53E of which 11 have been delivered, replaced the KV 107. Additional types include the LC-90 which are operated in the transport role and the U-36 which is operating in the operational support role. In March 2008 came another major re-organisation. The eight remaining P-3 Kokutais were reduced to four front-line units, 1, 2, 3 and 5 Kokutai survived. Also all H-60 helicopter Kokutais and air base Kyunan Hikotais were disbanded and four new Kokutais were activated, each with several detachments. Nowadays the Kaijo Jietai is still operating a large fleet of P-3C Orions built by Kawasaki Heavy Industries which currently serve the four operational Kokutais as well as one training Kokutai. Additional special mission Orions serve two units at Iwakuni and the test unit at Atsugi. But the days for the Orion are numbered, some aircraft are withdrawn from use at Atsugi and several examples even scrapped. Kawasaki and the TRDI are in full swing with testing its successor, this time an indigenous designed and developed model, the Kawasaki P-1. Flight testing of this aircraft finished March 2013 and 51 Kokutai is now performing operational tests. 5 Kokutai at Naha is said to receive the first examples after all testing has finished. The SH-60J Sea Hawk is slowly being replaced by the locally updated SH-60K variant and combined fleet is also totalling 100 units. Also the Merlin was introduced, at present supplementing the MH-53Es but at some point in time replacing it as well. Latest helicopter entering service is the Eurocopter EC-135 (TH-135) and it is replacing the OH-6D/DA at 211 Kyoiku Kokutai. As with the Japanese Air Force, today also the Kaijo Jietai is sometimes seen outside Japanese borders on international missions, e.g. the anti-piracy P-3 detachment in Djibouti.

Serial number System
JMSDF aircraft are identified by a four-digit serial number which appears on both sides of the vertical tail and in abreviated form (last two only) in large digits on the fuselage. The first digit of the full serial denotes the primary role, as follows:

  Primary role
1 not used
2 ASW, single-engine
3 not used
4 ASW, two-engined
5 ASW, four-engined
6 trainer
7 communication/trainer
8 helicopter
9 utility/liaison

Source Japanese Air Arms 1952-1984 by Akira Watanabe

Kaijō Hoan-chō - 海上保安庁

One of the first semi military agencies Japan was allowed to set up after the war was a unit dedicated to protect the coast-lines of Japan. It was founded in 1948 as the Japan Maritime Safety Agency under the control of the Ministry of Land, Infrastructure, Transport and Tourism, its English name changed to Japan Coast Guard in 2000. Initially only ships were obtained, MSA minesweepers were sent to Korea under UN flag in 1950. Presently about 12.000 personnel work for the Japan Coast Guard, which is headquartered in Tokyo.

The Japan Coast Guard is ensuring safety and security at sea by providing Maritime Patrol and Search and Rescue services, covering approximately 4.470.000 km2.

Photo: Scramble

The JCG has divided Japan into eleven Regions. Each region has its own Regional Coast Guard HQ and various CG Offices, CG Stations and CG Air Stations. Besides around 450 vessels, some of the larger ones capable of helicopter operations, the JCG operates some seventy aircraft, both fixed wing and helicopters. All are civil registered but also carry a unique code. Unfortunately the code is no clue to the Region a specific aircraft is assigned. Every aircraft also has a name, usually painted on the nose below the cockpit, which is specific for a certain Region, even for an Air Station or ship in that Region. When an aircraft is transferred to another Region, its name will change to that of its new Region. However this name is in Japanese characters and so for most Western spotters it is still impossible to get the exact unit. Our JCG database provides you with the Hiragana characters and with the Western equivalent per character, so NOT with the exact pronunciation or translation.

Initial equipment were surplus Beech 18 variants, augmented by various Bell and Sikorsky helicopters, including the locally manufactured single engine S-62. These were gradually replaced and during the eighties types in use included the YS-11, Shorts Skyvan, Beech 200 and Bell 206/212. More recent acquisitions to replace or augment older types are the DH-8, Gulfstream V, Falcon 900, SAAB 340, Beech 350, Bell 412, Eurocopter Super Puma variants and AW139. Most recently the JCG aquired the Bell 505 and Cessna 172S and now trains its own aircrew. In 2019 the Falcon 2000MSA will join the fleet.

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