Japanese Army Air Force Designations of the Second World War

Type Number System
Kitai System
Popular Names
Allied Codenames
Type Number List
Ki Number List

The Japanese Army Air Force used three overlapping aircraft designation systems – the Type number, based on the year the aircraft was accepted, the Kitai, or airframe number, allocated while a project was under development, and a series of popular names adopted just after the start of the Pacific War. A fourth name system was adopted by the Allies, in which each aircraft was given an easy to remember code name.

Type Number System

The Type Number system was adopted in 1927, and was based on the year in which a particular design was accepted by the Japanese Army Air Force. In the Japanese calendar 1927 was 2587, and so aircraft accepted in that year were given the designation Type 87 (the Japanese New Year had been moved to 1 January, so the years overlap perfectly). In 1940 (Japanese 2600) the Army used the designation Type 100 (while the Navy used Type 0). From 1941 only the last digit was used, starting with Type 1.

The Type Number was supplemented by a short description of the type’s function, which before the introduction of the Kitai system was the only way to distinguish between different types of aircraft accepted from the same manufacturer in a particular year – in 1928 this included the Kawasaki Army Type 88 Reconnaissance and Type 88 Light Bomber types.

All later versions of the same aircraft retained the same type number, regardless of when they entered service. This even applied to versions that were produced for different purposes, such as the Tachikawa Ki-54 Army Type 1 Advanced Trainer, which was also produced as a Operations Trainer, Transport and Patrol Bomber.

Major models of the same aircraft were distinguished by a Model number, with versions of the basic model getting a Kaizo (modification) symbol. The first version of the Mitsubishi Ki-67 to enter service was thus the Army Type 4 Heavy Bomber Model 1A, followed by the Model 1B, while a more advanced version planed for 1946 would have been the Model 2. From 1932 the model numbers used in the Type system matched the model designations used in the Kitai system.

Kitai System

While Type designations were only given to aircraft that were accepted for service, the Kitai (airframe) system of 1932 was used for every aircraft developed for the Japanese Army. The airframe, or Ki numbers, was allocated in sequence until 1944, and randomly after that.

The basic Ki number would apply to the prototype and early development aircraft. The prototype of the Tony was thus the Ki-61. As with the Type system each version was given a model number (a Roman numeral) and a subtype (a Japanese character, normally replaced by the equivalent English letter). The first production version of the Tony was thus the Ki-61-Ia.

Major modifications that were not considered worthy of a new model number were marked as remodelled (KAI, from the first two Japanese letters of Kaiso, remodel), as with the Ki-61 Hien (Tony). Here the second production version was the Ki-61-Ib and the third was the Ki-61-I KAIc. KAI was not used in the Type system, so I KAI c was simply Model IC.

In the original Japanese versions, Ki was a single Japanese character, followed by Arabic numerals for the actual Ki number, Roman numerals for the models and Japanese characters for the subtypes, with no punctuation needed. English translations use Ki-61-Ia or K.61-Ia interchangeably.

Popular Names

The Kitai and Type number systems remained in use until the end of the Second World War, but soon after the start of the Pacific War the Japanese Army realised that it needed shorter, easier to remember and more dramatic names for use in public announcements.  The names were allocated randomly, with most coming from flying creatures (Donryu or Storm Dragon) or weather (Hayate or Gale)

Allied Codenames

The famous Allied codenames were adopted during 1942 in an attempt to end the confusion caused by a tendency to describe all Japanese fighters as Zeros and bombers as Mitsubishis. Very little was known about the Japanese aircraft industry before the start of the fighting, and many of the aircraft types were unfamiliar. The code name system was developed by Captain Frank T. McCoy Jr, of Nashville Tennessee, who in the summer of 1942 was appointed head of the Materiel Section, Directorate of Intelligence, Allied Air Forces, Southwest Pacific Area, Melbourne (Australia). Existing aircraft were allocated code names during 1942, and new aircraft were added to the list when they were identified. A number of codes were allocated to obsolete or none-existence aircraft, and one was allocated to the Messerschmitt Bf 109, which was widely expected to appear in the Pacific.

The Allied codenames were allocated according to a simple pattern – male first names for fighters and reconnaissance seaplane, tree names for trainers, bird names for gliders and female first names for bombers, flying boats, reconnaissance aircraft and transports.

Type Number List

Type 87 (1927)

Kawasaki Army Type 87 Night Bomber
Mitsubishi Army Type 87 Light Bomber
 
Type 88 (1928)

Kawasaki Army Type 88 Reconnaissance Biplane
Kawasaki Army Type 88 Light Bomber

Type 91 (1931)

Nakajima Army Type 91 Fighter

Type 92 (1932)

Kawasaki Army Type 92 Fighter
Mitsubishi Ki-20 Army Type 92 Heavy Bomber
Mitsubishi Army Type 92 Reconnaissance Aircraft (2MR8)

Type 93 (1933)

Mitsubishi Ki-1 Army Type 93 Heavy Bomber
Kawasaki Ki-3 Army Type 93 Single-engined Light Bomber
Mitsubishi Ki-2 Type 93 Twin-engine Light Bomber

Type 94 (1934)

Nakajima Ki-4 Army Type 94 Reconnaissance Aircraft

Type 95 (1935)

Nakajima-Fokker Ki-6 Type 95-2 Crew Trainer
Tachikawa Ki-9 Army Type 95-1 Medium Grade Trainer
Kawasaki Ki-10 Army Type 95 Fighter
Tachikawa Ki-17 Army Type 95-3 Primary Trainer “Cedar”

Type 97 (1937)

Mitsubishi Ki-15 Army Type 97 Command Reconnaissance Plane “Babs”
Mitsubishi Ki-21 Army Type 97 Heavy Bomber
Nakajima Ki-27 Army Type 97 Fighter
Mitsubishi Ki-30 Army Type 97 Light Bomber “Ann”
Nakajima Ki-34 Army Type 97 Transport

Type 98 (1938)

Kawasaki Ki-32 Army Type 98 Single-engined Light Bomber
Tachikawa Ki-36 Army Type 98 Direct Co-operation Plane

Type 99 (1939)

Kawasaki Ki-48 Army Type 99 Twin-engined Light Bomber
Mitsubishi Ki-51 Army Type 99 Assault Plane
Tachikawa Ki-55 Army Type 99 Advanced Trainer

Type 100 (1940)

Mitsubishi Ki-46 Army Type 100 Command Reconnaissance Plane
Mitsubishi Ki-46-II Army Type 100 Operations Trainer
Mitsubishi Ki-46-III Kai Army Type 100 Air Defence Fighter
Mitsubishi Ki-46-IIIb Army Type 100 Assault Plane
Nakajima Ki-49 Army Type 100 Heavy Bomber Donryu (Storm Dragon)
Mitsubishi Ki-57 Army Type 100 Transport

Type 1 (1941)

Nakajima Ki-43 Army Type 1 Fighter Hayabusa (Peregrine Falcon)
Tachikawa Ki-54 Army Type 1 Advanced Trainer
Tachikawa Ki-54 Army Type 1 Operations Trainer
Tachikawa Ki-54 Army Type 1 Transport “Hickory”
Tachikawa Ki-54 Army Type 1 Patrol Bomber
Kawasaki Ki-56 Army Type 1 Freight Transport
Kokusai Ki-59 Army Type 1 Transport

Type 2 (1942)

Nagajima Ki-44 Army Type 2 Single-seat Fighter
Kawasaki Ki-45 Army Type 2 Two-seat Fighter Toryu (Dragon Killer)
Mansyu Ki-79 Army Type 2 Advanced Trainer

Type 3 (1943)

Kawasaki Ki-61 Army Type 3 Fighter Hien (Swallow)
Kokusai Ki-76 Army Type 3 Command Liaison Plane

Type 4 (1944)

Mitsubishi Ki-67 Army Type 4 Heavy Bomber Hiryu (Flying Dragon)
Nakajima Ki-84 Army Type 4 Fighter Hayate (Gale)
Kawasaki Ki-102b Army Type 4 Assault Plane

Type 5 (1945)

Kawasaki Ki-100 Army Type 5 Fighter

Ki Number List

Help - F.A.Q. - Contact Us - Search - Recent - About Us - Privacy