Imperial Japanese Army Air Service
The Imperial Japanese Army Air Service (often called the Imperial Japanese Army Air Force (大日本帝國陸軍航空隊、大日本帝國陸軍航空部隊 Dainippon Teikoku Rikugun Kōkūtai,Dainippon Teikoku Rikugun Kōkūbutai ) (IJAAS or IJAAF), was the land-based aviation force of the Imperial Japanese Army. As with the IJA itself, the IJAAF was developed along the lines of Imperial German Army Aviation so its primary mission was to provide tactical close air support for ground troops while maintaining a limited air interdiction capability. The JAAF also provided important reconnaissance support for the Army. However, the Army Air Service usually did not control the light aircraft or balloons deployed and operated by the Imperial Japanese Army artillery battalions as spotters or observers. Although the Army Air Service engaged in limited strategic bombing of major Chinese cities such as Shanghai and Chongqing in the early stages of the Second Sino-Japanese War, this was not its primary mission, and it lacked the heavy strategic bombers as were later deployed by the United States Army Air Forces. The Imperial Japanese Navy Air Service was responsible for long-range strikes and strategic air defense and it was not until the later stages of the Pacific War that both services attempted anything like integrated air defense.
The Imperial Japanese Army made use of hot air balloons for observation purposes in the Russo-Japanese War of 1904-1905 and purchased its first aircraft, a Farman biplane, in 1910. However, serious interest in military aviation did not develop until after World War I. Japanese military observers in Europe were quick to spot the advantages of the new technology, and after the end of the war, Japan purchased large numbers of surplus military aircraft, including Sopwith 1½ Strutters, Nieuport Bebes, and Spads.
Japanese army aviation was organized into a separate chain of command within the Ministry of War of Japan in 1919, and aircraft were being used in combat roles during the 1920 Siberian Intervention against the Bolshevik Red Army near Vladivostok.
The first aircraft factory in Japan, Nakajima Aircraft Company, was founded in 1916 and later obtained a license to produce the Nieuport 24 and Nieuport 29C1 as well as the Hispano-Suiza engine. Nakajima later license-produced the Gloster Gannet and Bristol Jupiter. Similarly, Mitsubishi Heavy Industries started producing aircraft under license from Sopwith in 1921, and Kawasaki Heavy Industries started producing the Salmson bomber from France, and hired German engineers such as Dr. Richard Vogt to produce original designs such as the Type 88 bomber. Kawasaki also produced aircraft engines under license from BMW. By the end of the 1920s, Japan was producing its own designs to meet the needs of the Army, and by 1935 it had a large inventory that was technically sophisticated.
By 1941, the Japanese Army Air Force had about 1,500 combat capable aircraft. During the first years of the war, Japan continued technical development and deployment of increasingly advanced aircraft and enjoyed air superiority over most battlefields due to the combat experience of its crews, plus the low numbers and lack of preparation of the allied forces.
However, as the war continued, the industrial limitation of the country in comparison with the Allies, while still in combat in different locations, as well as bombing of the Japanese home islands made Japan unable to maintain a competitive volume of aircraft. Experienced crews were lost to attrition in combat, new ones could not be trained due to the lack of fuel and time, and towards the end of its existence the JAAF resorted to kamikaze attacks against overwhelmingly superior Allied forces.
World War II Aircraft 
- Nakajima Ki-27 中島 キ27 九七式戦闘機 (Type 97 Fighter) Nate
- Nakajima Ki-43 中島 キ43 一式戦闘機 隼 (Type 1 Fighter "Hayabusa") Oscar
- Nakajima Ki-44 中島 キ44 二式単座戦闘機 鍾馗 (Type 2 Single seat Fighter "Shōki") Tōjō
- Kawasaki Ki-45 Kai 川崎 キ45改 二式複座戦闘機 屠龍 (Type 2 Two-seat Fighter "Toryū") Nick
- Kawasaki Ki-61 川崎 キ61 三式戦闘機 飛燕 (Type 3 Fighter "Hien") Tony
- Nakajima Ki-84 中島 キ84 四式戦闘機 疾風 (Type 4 Fighter "Hayate") Frank
- Kawasaki Ki-100 川崎 キ100 五式戦闘機 (Type 5 Fighter)
- Mitsubishi Ki-109 三菱 キ109 試作特殊防空戦闘機 (Experimental heavy fighter interceptor)
- Mitsubishi Ki-21 三菱 キ21 九七式重爆撃機 (Type 97 Heavy Bomber) Sally
- Mitsubishi Ki-30 三菱 キ30 九七式軽爆撃機 (Type 97 Light Bomber) Ann
- Kawasaki Ki-32 川崎 キ32 九八式軽爆撃機, (Type 98 Light Bomber) Mary
- Kawasaki Ki-48 川崎 キ48 九九式双発軽爆撃機 (Type 99 Twin-engined Light Bomber) Lily
- Nakajima Ki-49 中島 キ49 一〇〇式重爆撃機 呑龍 (Type 100 Heavy Bomber "Donryū") Helen
- Mitsubishi Ki-67 三菱 キ67 四式重爆撃機 飛龍 (Type 4 Heavy Bomber "Hiryū") Peggy
Forward air control aircraft:
- Mitsubishi Ki-51 三菱 キ51 九九式襲撃機 (Type 99 Assault plane) Sonia
- Kawasaki Ki-102 川崎 キ102 五式双発襲撃機 (Type 5 Twin-engined Assault plane) Randy
- Nakajima Ki-34 中島 キ34 九七式輸送機 (Type 97 Transporter) Thora
- Mitsubishi Ki-57 三菱 キ57 一〇〇式輸送機 (Type 100 Transporter) Topsy
- Kawasaki Ki-56 川崎 キ56 一式貨物輸送機 (Type 1 Cargo aircraft) Thalia
- Kokusai Ki-59 国際 キ59 一式輸送機 (Type 1 Transporter) Theresa
- Mitsubishi Ki-15 三菱 キ15 九七式司令部偵察機 (Type 97 Army HQ Reconnaissance plane) Babs
- Tachikawa Ki-36 立川 キ36 九八式直接協同偵察機 (Type 98 Reconnaissance plane) Ida
- Mitsubishi Ki-51 三菱 キ51 九九式軍偵察機 (Type 99 Reconnaissance plane) Sonia
- Mitsubishi Ki-46 三菱 キ46 一〇〇式司令部偵察機 (Type 100 Army HQ Reconnaissance plane) Dinah
- Tachikawa Ki-9 立川 キ9 九五式一型練習機 (Type 95 Model 1 Intermediate trainer) Spruce
- Tachikawa Ki-17 立川 キ17 九五式三型練習機 (Type 95 Model 3 Basic trainer) Cedar
- Tachikawa Ki-55 立川 キ55 九九式高等練習機 (Type 99 Advanced trainer) Ida
- Tachikawa Ki-54 立川 キ54 一式双発高等練習機 (Type 1 Twin-engine advanced trainer) Hickory
- Manshū Ki-79 満州 キ79 二式高等練習機 (Type 2 Advanced trainer)
- Kokusai Ki-76 国際 キ76 三式指揮連絡機 (Type 3 Command-control/Liaisonal plane) Stella
- Kayaba Ka-1 萱場 カ号観測機 (Ka-Gō Artillery-spotter)
Army Aeronautical Department Sections 
- Commander-in-Chief of Army Air Service Office
- Air Service Staff Department
- General Affairs and Administrative Department
- Inspectorate General of Aviation
- General Affairs Unit of Inspectorate of Army Aviation
- Air Training and Instruction Department
- Imperial Japanese Army Air Service Academy
- Supply Bureau
- Tachikawa Army Air Arsenal
- Army Air Transport Department
- Army Air Intelligence Department
Operational Organization 
Before World War I, the basic unit of the Army Air Service was the Air Battalion (航空大隊 Kōkū Daitai ), each consisting of two squadrons (中隊 Chutai ) with nine aircraft each, plus three reserve aircraft and three earmarked for use by the headquarters, for a total of 27 aircraft per battalion. The officer commanding the chutai was the Chutaicho, whose rank was usually that of captain. The commander's aircraft often had distinctive markings, often a partly or totally scarlet, red, orange or yellow tail.
In a reorganization of 1927-05-05, the Air Regiment (飛行連隊 Hikō Rentai ) was created, each consisting of two battalions, with each battalion consisting of up to four squadrons. Each Air Regiment was a mixed purpose unit, consisting of a mixture of fighter and reconnaissance squadrons.
With the start of the Second Sino-Japanese War in 1937, operational conditions favored the use of many small units, resulting in the creation of many independent Air Battalions (独立飛行大隊 Dokuritsu Hikō Daitai ) or even independent squadrons (独立飛行中隊 Dokuritsu Hikō Chutai ), each with its own distinctive markings.
In August 1938, a complete re-organization of the Army Air Service resulted in the creation of the Air Combat Group (飛行戦隊 Hikō Sentai ), which replaced all of the former Air Battalions and Air Regiments. Each Air Combat Group was a single-purpose unit consisting typically of three Squadrons, divided into three flights-小隊-shōtai of three aircraft each. Together with reserve aircraft and the headquarters flight, an Air Combat Group typically had 45 aircraft (fighter) or up to 30 aircraft (bomber or reconnaissance). Two or more Air Combat Groups formed an Air Division (飛行団 Hikōdan ), which, together with base and support units and a number of Independent Squadrons, formed an Air Corps (飛行集団 Hikō Shudan ).
In 1942, the Air Corps were renamed Air Divisions (飛行師団 Hikō Shidan ), to mirror the terminology for infantry divisions, but the structure remained the same. Two Air Divisions, together with some independent units made an Air Army (航空軍 Kōkū gun ).
Throughout most of the Pacific War, the Japanese Army Air Service was organized into four Air Armies, with two more added in the final stages of the war:
- 1st Air Army – HQ Tokyo, basing in the Kanto Plain covering the Japanese home islands, Taiwan, Korea, Chishima, and Karafuto.
- 2nd Air Army - HQ Hsinking, covering Manchukuo
- 3rd Air Army - HQ Singapore, covering Southeast Asia
- 4th Air Army - HQ Rabaul, covering the Solomon Islands and New Guinea
- 5th Air Army - HQ Nanking, covering Japanese-occupied portions of southern and eastern China.
- 6th Air Army – on Kyūshū covering Taiwan and Okinawa
In April 1944, a reorganization of the Japanese Army Air Service occurred. Maintenance and ground service units, formerly a separate command, were merged into the Air Combat Group (Hiko Sentai). The flying squadrons of the Air Combat Group were re-designated as Attack Units (攻撃隊 Kogekitai ), and the ground units were designated Maintenance Units (整備隊 Seibutai ).
Other changes in the final stages of the war was the formation of “Special Attack Units” and "Air-shaking Units", which were short-lived units with their own names (often taken from Japanese mythology or history) and markings, but located within existing squadrons. These units were specially designated and trained with the mission of air-to-air ramming of Allied bomber aircraft. They usually had their armaments removed and their airframes reinforced.
In the final phase of the war, the Special Attack Units evolved into dedicated suicide units for kamikaze missions. Around 170 of these units were formed, 57 by the Instructor Air Division alone. Notionally equipped with 12 aircraft each, it eventually comprised around 2000 aircraft.
The final reorganisation of the took place during preparation for Opertation Ketsu-Go, the defence of the home islands in 1945 when all the Air Armies were combined under a centralised command of General Masakau Kawabe .
Special Operations Forces 
Teishin Shudan ("Raiding Group") was the IJA's special forces/airborne unit during World War II. The word teishin may be literally translated as "dash forward", and is usually translated as "raiding". It may also be regarded as similar to the "commando" designation in the terminology of other armies. The unit was a division-level force, and was part of the Imperial Japanese Army Air Service (IJAAS). The Teishin units were therefore distinct from the marine parachute units of the Special Naval Landing Forces.
'Giretsu' (義烈空挺隊 Giretsu Kūteitai ) was an airborne special forces unit of the Imperial Japanese Army formed from Army paratroopers, in late 1944 as a last-ditch attempt to reduce and delay Allied bombing raids on the Japanese home islands. The Giretsu Special Forces unit was commanded by Lieutenant General Kyoji Tominaga.
In 1940 the Japanese Army Air Service consisted of the following:
- 33,000 personnel
- Over 1,600 aircraft (including 1,375 first line combat aircraft).
- The aircraft were organized into 85 Squadrons;
- 36 fighter
- 28 light bomber
- 22 medium bomber
- Total military in August 1945 was 6,095,000 including 676,863 Army Air Service.
Army Air Arsenal 
The Japanese Air Army Force had one technical section: the First Tachikawa Air Army Arsenal, which was in charge of aviation research and development. The Arsenal included a testing section for captured Allied aircraft.
Army Escort-Aircraft Carriers 
Due to the poor relations between the Imperial Japanese Army and Imperial Japanese Navy, the Army found it necessary to procure and operate their own aircraft carriers for the purposes of providing escort and protection for Army transport shipping convoys. These escort/transport carriers, were converted from small passenger liners or merchant ships. These escort carriers possessed the capacity to operate from eight to 38 aircraft, depending on type and size, and were also used to transport personnel and tanks.
These vessels included the Taiyō Maru, Unyo Maru, Chuyo Maru, Kaiyō Maru, Shinyo Maru, Kamakura Maru, Akitsu Maru, Nigitsu Maru, Kumano Maru, Yamashiro Maru, Chigusa Maru, Shimane Maru, and Otakisan Maru and were operated by civilian crews with Army personnel manning the light and medium anti-aircraft guns.
Uniforms and equipment 
As an integral part of the IJA, the Army Air Service wore the standard Imperial Japanese Army Uniforms. Only flying personnel and ground crews wore sky blue trim and stripes, while officers wore their ranks on sky blue patches.
See also 
- List of military aircraft of Japan
- Giretsu special forces
- Teishin Shudan (Army air service airborne/commando division)
- Hikotai Transport Unit
- Inspectorate General of Aviation
- List of Radars in use by Imperial Japanese Army
- List of Bombs in use by Imperial Japanese Army
- List of weapons on Japanese combat aircraft
- List of Aircraft engines in use of Japanese Army Air Force
- List of foreign aircraft tested by Japanese forces from 1930s to WW2
- List of Japanese trainer aircraft during World War II
- Japanese military aircraft designation systems
- Imperial Japanese Army Air Force Academy
- Air raids on Japan
- p.107, Skates
- Hata, Ikuhiko (2002). Japanese Army Air Force Units and Their Aces: 1931-1945. London: Grub Street. ISBN 1-902304-89-6.
- Mayer, S.L. (1976). The Rise and Fall of Imperial Japan. The Military Press. ISBN 0-517-42313-8.
- Sakaida, Henry (1997). Japanese Army Air Force Aces, 1937-1945. Botley, Oxfordshire, UK: Osprey Publishing. ISBN 1-85532-529-2.
- Skates, John Ray. The Invasion of Japan: Alternative to the Bomb. Columbia, South Carolina, USA: University of South Carolina Press, 1994. ISBN 0-87249-972-3.
- An introduction to the Japanese Army Air Force
- Images of Axis aircraft: German, Italian and Japanese Army and Navy
- Advanced Japanese aircraft
- General resources on Japanese aircraft
- Some captured aircraft, or aircraft in evaluation
- Japanese armaments, vehicles, aircraft, electronic warfare and some Japanese special weapon technology
- Mark Kaiser, 1997-98, "Unit structure of IJA Air Force" (self-published)