Nippon Rikukaigun - Imperial Japanese Army and Navy research by Eugen Pinak

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This 1943 USN intelligence report has many errors. Yet it is interesting period document, showing current US knowledge on Japanese Navy and Army air services. – Eugen Pinak

A.I.D. #42

August 1943

Op-35

ORGANIZATION AND RANK IN THE JAPANESE ARMY AND NAVY AIR SERVICES

Revision of Air Information Report # 2 published by the Air Information Branch of the Bureau of Aeronautics in March, 1943.

Prepared by

AIR INFORMATION DIVISION

OFFICE OF THE CHIEF OF NAVAL OPERATIONS

NAVY DEPARTMENT

WASHINGTON D.C.

ORGANIZATION AND RANK IN THE JAPANESE ARMY AND NAVY AIR SERVICES:

PREFACE

I. OPERATIONAL AIR UNIT TERMS EMPLOYED BY BOTH THE ARMY AND NAVY

1. SHOTAI (Section).

2. CHUTAI (Squadron).

3. DAITAI (Type Wing).

4. BUTAI (Force).

II. NAVAL AIR FORCE

1. Naval Aviation Hdqts. (KAIGUN KOKU HOMBU).

2. The Combined Fleet (RENGO KANTAI).

3. Third Fleet (DAI SAN KANTAI).

A. Ship-Borne Air Flotillas (Ship-Borne KOKUSENTAI).

B. Ship-Borne Air Groups, and Squadrons (CHUTAI).

4. Eleventh (Shore-Based) Air Fleet (DAI JUICHI KOKU KANTAI) and Twelfth (Shore-Based) Air Fleet (DAI JUNI KOKU KANTAI).

A. Shore-Based Air Flotillas (Shore-Based KOKUSENTAI).

B. Air Attack Forces (KUSHUBUTAI).

C. Base Air Force (KICHI KOKU BUTAI).

D. Shore-Based Air Groups (KOKUTAI).

E. DAITAI (Type Wings), Squadrons (CHUTAI), Sections (SHOTAI).

III. ARMY AIR FORCE

1. Army Aviation Hdqts. (RIKUGUN KOKU HOMBU).

2. Air Commands (KOKU HEIDAN), and Flying Divisions (HIKO SHIDAN).

3. Flying Brigades (HIKODAN), and Flying Regiments (HIKO SENTAI).

4. Type Wings (DAITAI), Squadrons (CHUTAI), Section (SHOTAI).

5. Task Forces (BUTAI).

6. Administrative Units.

7. Training Units.

IV. FLYING RANK - ARMY AND NAVY

1. Officers.

2. Enlisted Personnel

3. Illustrations.

Naval Air Service - Table A, Part I

Army Air Service - Table A, Part 2

GLOSSARY

PREFACE

The Preface to the March, 1943, edition of this Report stated: "This paper should not be considered, in any sense, a final disposition of the subject matter. On the contrary, it represents merely a tentative approach to the subject. Not only is further data concerning Japanese air organization likely to become available) but that organization is itself subject to constant change."

Since that Report was issued, more data has come to light, and further changes have taken place in the organization of the Japanese air forces. As a result, this revised version of Air Information Report No. 2 is being issued. Again, it is necessary to caution the reader that Japanese air organization is extremely complex and extremely flexible; almost any statement made in this paper may have to be reexamined in the light of new evidence or of changes which may take place in the Japanese air forces.

This paper has placed considerable emphasis on Japanese terms, in order to facilitate their handling by U.S. personnel. The confusion which has hitherto surrounded the subject of Japanese air organization has resulted, in large part, from the Japanese language itself.

It is obvious that the Japanese will write air unit terms, such as "section", in the pictorial characters of their own language. Japanese phonetic renderings of these characters, when written in Roman letters, are termed "Romaji". For example, the phonetic rendering of the charac­ters meaning "section" is SHOTAI. Such a Japanese Romaji term may be translated by a variety of English equivalents. It is therefore desirable to use, insofar as possible, the original Romaji terms, and not their English equivalents.

A further important source of the confusion surrounding the subject of Japanese air organization has been the too literal acceptance of statements concerning that organization made by Japanese sources.

In particular, the loose use of various organizational terms, such as BUTAI, which has both general and specific meanings, and such as SENTAI, which describes ground and surface as well as air units, should be noted. Also the tendency of Japanese sources to identify Japanese units in a variety of ways - by the name of the C.O. (this is especially frequent), the name of the current station, the name of the parent unit, or a numerical designation, must be taken into account. The possibility of misunderstandings arising from the above practices should be borne in mind by U.S. personnel when confronted by seemingly contradictory evidence concerning Japanese air organization.

This paper does not attempt any detailed description of the strength and composition of specific units, except insofar as such description may serve to illustrate general Japanese practice.

The composition of any air unit may change radically from time to time, as losses are experienced, and as its component elements are reassigned or reinforced. For this reason, the identification of a given unit should not be taken as a necessary indication of that unit's strength; the unit's composition may have been changed since its strength was last ascertained. Because of the frequency of such changes, any analysis of the strength and disposition of all but the very largest Japanese air units would serve no useful purpose in a paper of this type and classification.

Any analysis of Japanese air organization should be based on a knowledge of Japanese naval organization. Readers desiring to pursue this latter subject further are referred to confidential Serial 69-43, or the latest revision thereof, issued by the Office of Naval Intelligence.

NOTE: A clear understanding of this paper will be more easily secured if constant reference is made to parts 1 and 2 of Table A, while reading Chapters I - III of the text.

-I-

OPERATIONAL AIR UNIT TERMS EMPLOYED BY BOTH THE ARMY AND NAVY

1. SHOTAI (Section).

The smallest Japanese air unit is the SHOTAI, which is composed of one to four (usually three) aircraft. SHO means "small", TAI is a suffix meaning "unit". Thus SHOTAI means "small unit". The nearest U. S. equivalent is the section. The SHOTAI exists only as a unit when in flight.

2. CHUTAI (Squadron).

Two to four (usually three) SHOTAI make up a CHUTAI, which thus contains an approximate total of 6-12 aircraft. CHU means "center" or "middle", more rarely "mean" or "medium". Thus CHUTAI would mean "medium sized unit". The nearest U. S. equivalent is the squadron. In Army, squadron, both as an administrative and as a tactical unit, is termed a CHUTAI. In the Navy a squadron is known tactically as a CHUTAI, but administratively as a BINTAI.

3. DAITAI (Type Wing).

Two to three CHUTAI (squadrons), when in flight, may form a DAITAI. Dai means "largeness or "greatness", hence DAITAI is literally "large unit", DAITAI is translated as "Type Wing"; it is the largest air unit necessarily made up of exclusively one type of aircraft.

This SHOTAI-CHUTAI-DAITAI pattern is extremely flexible, depending on the individual operating requirements of the units in question. One medium bomber DAITAI operating in northeast Australia is believed to have been composed as follows:

1st CHUTAI -

1 SHOTAI of three aircraft.

2 SHOTAI of four aircraft each.

TOTAL: 11 aircraft.

2nd CHUTAI -

1 SHOTAI of two aircraft.

3 SHOTAI of three aircraft each.

TOTAL: 11 aircraft.

3rd CHUTAI -

1 SHOTAI of one aircraft.

4 SHOTAI of three aircraft.

TOTAL: 13 aircraft.

GRAND TOTAL: 35 aircraft.

It is evidently the Japanese intent to organize these lower operational echelons in pyramids of threes; this intent is reflected in their flying formations.

4. BUTAI

BUTAI, meaning "force", is a term used alone, or in conjunction with other terms, by both the Japanese Amy and Navy, to describe rather large air task forces. Army BUTAI, and Navy BUTAI, KUSHUBUTAI (Air Attack Forces), and KICHI KOKU BUTAI (Base Air Forces) will be fully described in Chapters II and III of this paper.

In addition to the above meanings, BUTAI is often used, in a rather general sense, to refer to any air unit. In this sense, BUTAI is generally prefaced by the name of the unit's commander e.g. WATANABE BUTAI (the Watanabe air unit). When used in this way, BUTAI contains no implications as to the size and type of the unit in question - it is rather vague and non-descriptive term.

This emphasizes again the necessity for referring to Japanese air unit terms in Romaji, unless an authoritative translation for such Romaji has already been disseminated.

-II-

NAVAL AIR FORCE

1. Naval Aviation Headquarters (KAIGUN KOKU HOMBU) and the Combined Naval Air Corps (RENGO KAlGUN KOKU SOTAI).

The Naval Air Service is an integral part of the Navy, its particular problems being han­dled by the Naval Aviation Headquarters (KAIGUN KOKU HOMBU), which are headed by a Vice-Admiral. KAIGUN is "Navy”, KOKU is "aviation", and HOMBU is "Headquarters".

These Headquarters were reorganized during October, 1942, to give the Vice-Admiral Command­ing authority over air operations, as well as over aviation personnel and materiel. This followed a similar reorganization of the Army Air Force Headquarters, which had taken place in May, 1942.

The head of the Naval Aviation Headquarters may be compared to our own Deputy Chief of Naval Operations for Air.

The head of the Naval Aviation Headquarters is co-equal in authority to the Navy Minister and the Chief of the Naval General Staff. Each of these three officers is directly responsible to the Emperor. Together they constitute the High Command of the Japanese Navy.

Naval air training is carried on by the Combined Naval Air Corps (KAIGUN RENGO KOKU SOTAI), located in Japan proper, and now headed by a Prince of the Imperial Family. This Corps answers directly to the Naval Aviation Headquarters. It consists of Combined Air Groups (RENGO KOKUTAI), which are the units through which its training program is executed.

2. The Combined Fleet (RENGO KANTAI).

Under these three officers come: (a) The C-in-C, Combined Fleet, (b) the C-in-C, Southwest Area FIeet, (Burma, Malaya, Indo-China, N.E.I., Philippines), (c) the C-in-C, China Seas Fleet, (d) the Commanders of Home Defense Forces in Japan proper.

Airflot 23, (KOKUSENTAI 23), known tactically as the East Indies Air Force (East Indies KOKU BUTAI), is attached to the 2nd Southern Expeditionary Fleet of the Southwest Area Fleet. Airflot 23 consists of one XCVS and two shore-based Air Groups (KOKUTAI).

With this exception, the majority of Japanese naval aviation, like the majority of Japanese naval surface strength, comes under the Combined Fleet. RENGO is "Combined"; KANTAI is "Fleet". This fleet is broken down administratively into six surface Fleets, two Air Fleets, and one sub­marine Fleet, and tactically into various task forces and task organizations.

Among the surface Fleets is the Third Fleet (DAI SAN KANTAI), which includes all Japanese carriers and hence most Japanese naval ship-borne air strength.

The two Air Fleets are the 11th (DAI JUICHI KOKU KANTAI), and the 12th (DAI JUNI KOKU KANTAI). These two Air Fleets together contain most of the Japanese Navy's shore-based air strength. The Eleventh Air Fleet functions in the South and Southwest Pacific; the Twelfth Air Fleet, which is considerably smaller, was recently created to meet the growing American threat to the Kuriles.

These Fleets and Air Fleets are commanded by Vice-Admirals (KAIGUN CHUSHO). These same officers exercise tactical command over the task forces which parallel, to a large extent, the organization of these administrative Fleets.

KOKU stands for "air", DAI SAN is "third", DAI JUICHI is "eleventh", DAI JUNI is "twelfth".

3. Third Fleet (DAI SAN KANTAI).

The Third Fleet contains all Japanese carriers as well as one Batdiv, two Crudiv's and five Desdiv's. It also includes Airflot 50, containing two shore-based Air Groups and one aircraft carrier, which are devoted to ASW and to the training of carrier squadrons, and three ACV's which are probably used as aircraft transports. The continued existence of Airflot #50 is currently in doubt.

In addition to the aircraft carriers, which make up the Third Fleet, and to the seaplane carriers, to be described later, Japanese naval ship-borne air strength includes observation planes on various classes of warships, as follows:

It was at one time suggested that these planes cams under the administrative cognizance of the Third Fleet. There is no evidence to support this view.

A. Ship-borne Air Flotillas (Ship-borne KOKUSENTAI).

The Third Fleet, the Eleventh Air Fleet, and probably the Twelfth Air Fleet are divided, administratively, into KOKUSENTAI, each commanded by a Rear Admiral (KAIGUN SHOSHO). KOKU means "aviation", and SENTAI means "division"; KOKUSENTAI is translated "Air Flotilla" or "Airflot".

It is believed that KOKUSENTAI 1-10 are reserved for Cardivs; KOKUSENTAI 11-20 for seaplane and training commands; KOKUSENTAI 21-30 for shore-based Air Flotillas. Currently only KOKUSENTAI 1 and 2 (Cardivs), 14 and 18 (Training), 21, 22, 23, 24, 25, and 26 (Shore Based Airflots) are operational.

Two or three carriers, (one Cardiv), make up one ship-borne KOKUSENTAI. The total air complement of two or three Japanese carriers would, range from about 100 to 200 planes, depending on the carriers involved. Thus a carrier KOKUSENTAI is about 'the same size as a shore-based. KOKUSENTAI. There is some evidence that Cardivs (Carrier KOKUSENTAI) actually operate as tactical units.

The Third Fleet contains two Cardivs, each containing 2-3 carriers. The number of carriers in any given Cardiv varies over a period of time; occasionally one carrier will operate alone directly tinder the Third Fleet, without being a part of either of its Cardivs.

There were, until recently, two Seaplane KOKUSENTAI, each made up of 4-6 seaplane carriers (each carrying 10-14 planes). These Seaplatendiv's have recently been disbanded, and their component vessels re-assigned as elements of other Japanese fleets. The largest seaplane concentration (2CVS, and 5 XCVS) is now to be found in the train of the Combined Fleet.

The complements of Japanese seaplane carriers are as follows:

SEAPLANE CARRIERS

CONVERTED SEAPLANE CARRIERS

b. - Estimated.

B. Ship-borne Air Groups and Squadrons (CHUTAI).

A shore-based KOKUSENTAI (Alrflot) breaks down into several shore-based KOKUTAI (Air Groups). It has been suggested that the air complement of a ship-borne KOKUSENTAI (Cardiv) is similarly broken down into several ship-based KOKUTAI (Air Groups), each comprising the air complement of one aircraft carrier.

However, there is no evidence of the existence of any Air Groups other than the named and numbered Groups referred to later in this text. Certain of these Air Groups, based in Japan, are training units, and some of these latter serve exclusively to replenish carrier strengths. Units of operational naval Air Groups might also be embarked on carriers if the tactical situation so demanded. Thus the air complement of one carrier might be made up of Squadrons drawn from several different Air Groups.

The Squadrons embarked on one carrier, regardless of their original administrative affiliations, will form one tactical unit while on that carrier. This tactical unit will be designated by the name of its carrier, and may be roughly compared to a U.S. carrier air group. Unlike the regular Japanese Air Group (KOKUTAI), it is not a permanent administrative unit.

The air complement of a Japanese carrier will vary (36-72 planes) according to the size of the carrier. Thus, as will be seen later, a Carrier-borne air unit varies within roughly the same limits as a shore-based KOKUTAI (Air Group):

4. Eleventh (Shore-baBed) Air Fleet (DAI JUICHI KOKU KANTAI), and the Twelfth (Shore-based) Air Fleet (DAI JUNI KOKU KANTAl).

The Eleventh Air Fleet, as previously indicated, includes most of the Navy's shore-based planes. It consists of shore-based Airflots 21, 22, 25, and 26. 3 APV's, and 2 DD's are also attached to this Air Fleet.

The Eleventh Air Fleet functions in the Melanesia - New Guinea area. Also in this area is the 8th Fleet, composed of cruisers and destroyers. These two fleets combine to form the South-east Area Fleet, which is commanded by the C-in-C, Eleventh Air Fleet. In the train of the South-east Area Fleet are 2 XCVS. It should be remembered that this organization is administrative, not tactical.

Administrative headquarters of the Eleventh Air Fleet are at Tinian, a small island south of Saipan; but C-in-C, Eleventh Air Fleet, has maintained his operational staff at Rabaul since August, 1942.

Recently the Twelfth (shore-based) Air Fleet has been created to meet the. menace arising from the U.S. seizure of Attu Island. The Twelfth Air Fleet is based in the Kuriles; it probably is made up of Airflot 24.

A. Shore-based Air Flotillas (Shore-based KOKUNSENTAI).

An Air Fleet is broken down, administratively, into KOKUSENTAI (Air Flotillas).

One Air Flotilla (abbreviated to Airflot), is made up of combat detachments from two to four Air Groups. The strength of the Airflot will depend on the fluctuating size of these detachments; it will generally total anywhere from 50 to 150 (more usually 75 to 125) planes.

Air Flotillas have auxiliary surface vessels, such as aircraft transports, attached to them for supply purposes. Thus, Airflots 22-26 each contain one APV, Airflots 23 and 26 each contain one CVS in addition.

B. Air Attack forces (KUSHUBUTAI).

The Eleventh and Twelfth Air Fleets' planes are organized administratively into five Airflots; they are also organized tactically into five Air Attack Forces (KUSHUBUTAI). KUSHU is "attack", BUTAI is "force". Each Airflot is related to one Air Attack Force.

Airflot 21 - 1st Air Attack Force

Airflot 22 - 2nd Air Attack Force

Airflot 24 - 4th Air Attack Force

Airflot 25 - 5th Air Attack Force

Airflot 26 - 6th Air Attack Force

The Rear Admiral commanding each Airflot is also the head of the corresponding Air Attack Force, and it is believed that each Air Flotilla serves as the administrative fountain-head for the Air Attack Force to which it is related. While the Air Flotillas are administrative units, the Air Attack Forces are exclusively tactical in function. Like all task forces, they are ex­tremely flexible in size and composition. Each Air Attack Force is made up, in the main, of units drawn from its corresponding (administrative) Air Flotilla.

Airflot 23, it will be remembered, is a part of the Southwest Area Fleet, and is known tactically as the East Indies Force (BUTAI) or Air Force (KOKU BUTAI). It would appear that the East Indies BUTAI is an air task force type on roughly the same level as the Air Attack Forces, though probably less mobile; being rather permanently stationed in the area from which it takes its name. The appearance of other such BUTAI (or KOKU BUTAI) is possible.

C. Base Air Force (KICHI KOKU BUTAI).

It is believed that the Base Air Force (KICHI KOKU BUTAI) is a task force type quite dis­tinct from the above-mentioned BUTAI or KOKU BUTAI.

In a recent South Pacific operation, the C-in-C, Eleventh (shore-based) Air Fleet, function­ed tactically as Commander, Base Air Force, which was a task force embracing those of the Eleventh Air Fleet's Air Attack Forces taking part in this particular operation.

Evidently when a considerable number of naval land-based airplanes are called on to partici­pate in an operation under one unified command, they may be organized into a large air task force, termed the Base Air Force (KICHI KOKU BUTAI). This task force will be of considerably greater scope than either a Force (BUTAI), or an Air Attack Force (KUSHUBUTAI), either or both of which might be among its component elements. The Base Air Force might be termed the tactical equivalent of the administrative Air Fleet.

It is possible, however, that during a future operation the term Base Air Force maybe used with a very different meaning.

It should be re-emphasized that the KOKU KANTAI (Air Fleet) and the KOKUSENTAI (Airflot) are permanent elements in the administrative organization of the Japanese naval air service, whereas the KUSHUBUTAI (Air Attack Force), the KOKU BUTAI (Air Force), and the KICHI KOKU BUTAI (Base Air Force) are task forces types created temporarily to meet the needs of the current Pacific struggle.

The above Base Air Force should not be confused with the Base Groups - whioh are units, mainly composed of seaplanes, assigned to various Japanese bases in the Pacific. Their exact status is obscure, their role is believed largely defensive. It is possible that they have some operational relationship to the 11th Air Fleet.

D. Shore-based Air Groups (Shore-based KOKUTAI).

One KOKUSENTAI (Airflot) breaks down into two or three KOKUTAI (Air Groups), or detachments - usually Type Wings - thereof. KOKU is "air", TAI is "unit"; the Japanese sometimes abbreviate KOKUTAI to KU.

Air Groups are commanded by Naval Captains (KAIGUN TAISA), and are the basic administrative units of the Japanese naval air service. Air Groups (KOKUTAI) are of two types:

(1) Those which have permanent home stations in the Japanese Empire and which are sometimes known by the names of these stations;

(2) "Specially Mobilized" Air Groups (TOKUSETSU KOKUTAI), which are numbered and have known by their numerical designations. It is believed that these Groups may have been established at air stations outside the Empire, as the Japanese have shown some inclination to name air stations within the Empire, and to number those outside the Empire.

Recently, the Japanese have introduced very high numeral designations for both named and numbered Air Groups. Named Air Groups are apparently now known by both their original names and their new numbers.

These new high numbers serve as a fairly reliable guide to the composition of the Air Groups involved; thus observation Groups are usually numbered in the 100’s, fighter Groups in the 200's, mixed fighter-bomber Groups in the 500's, bomber Groups in the 700's, flying boat Groups in the 800's, float plane Groups in the 900's. But there are lots of exceptions; the composition of many Air Groups is rather mixed.

This system, like all matters pertaining to the designation of naval air units, is of course, subject to constant change. The Japanese are intensely security-minded, nominal and numerical changes are continually introduced in the organization of their naval air force to conceal its real status.

The total number of Air Groups in active status will vary according to the strength of the Japanese air force. If heavy losses are experienced, certain Groups may drop out of the picture; if production and training out-run casualties, new Air Groups may be activated. Since the Air Group seldom functions as a combat unit, in its entirety, the total number of Air Groups in active status, and fluctuations therein, are matters of administrative, rather than operational, concern.

Air Groups do not necessarily consist of only one type of aircraft, and their size will vary within wide limits; some run as high as 150, others come as low as 18. Often, they will contain transport planes, in addition to one or more types of combat planes.

A further confusing factor is that the Air Group does not always function as one body; its combat detachments may be scattered among several different theaters of war.

Some of an Air Group's strength may be maintained at its home station, particularly if that station is in the Japanese Empire. These aircraft will have duties in connection with air raid defense and anti-submarine warfare; they will probably also engage in advanced operational train­ing. As the Air Group's home strength is increased by the addition of planes and air crews received from Japanese factories and training centers, that home strength will in turn be reduced by the despatch of the Air Group's combat detachments to various Air Flotillas.

It is sometimes difficult, when confronted with documentary evidence that a certain Air Group is a part of a given Airflot, to decide whether the entire Air Group, or merely one of its combat detachments, is involved. It is generally believed, however, that these are references to combat detachments of Air Groups, not to the total original establishments of the Air Groups concerned. These combat detachments may be made up of one or more Type Wings, or of lesser units - such as Squadrons.

One Airflot, for example, is thought to have been made up as follows: 3 bomber Type Wings (DAITAI) of 27-30 planes each; 5 fighter Type Wings; and one observation squadron (CHUTAI) of ten planes.

One Air Group had the following of its units attached to an Airflot: three fighter squadrons (15 planes each), and two torpedo squadrons (9 planes each).

Both these examples suggest that Air Flotillas are made up of Type Wings and/or Squadrons taken from several different Air Groups.

Certain Air Groups, by the way, do not seem to have any combat functions; they are merely training units, serving as replacement pools for other combat Air Groups, or for aircraft carriers Training Air Groups are believed to diverge somewhat in strength and composition form other Air Groups.

In considering lists of shore-based Air Groups and their aircraft strengths, one must therefore consider whether the Air Group in question is a training or a combat unit, and if the latter, whether its given aircraft strength represents the total original, establishment of the Air Group at its home base, or the present operating strength of one of its overseas detachments.

Often the operating detachment of an Air Group will be referred to in such a manner as to lead one to believe that it comprises the entire Air Group. At other times the original establish­ment of the entire Air Group may be given, without any clear indication that its operating detachments can claim but a fraction of that strength.

Of course there must always be borne in mind the possibility that tin Air Group will function its entirety as a combat unit of an Air Flotilla. This is probably more often true of Specially Mobilized Air Groups than of those which have bases within the Japanese Empire.

It has been suggested that operational detachments of Air Groups will approximate the following figures: A flying boat detachment: 12 aircraft, a floatplane detachment: 12-18 planes, a fighter detachment: 45 fighters with 6 recco's occasionally added. Medium bomber detachments will sometimes come as high as 45 planes; 27 is, however, the more normal figure; while dive bomber detachments usually have about 18 planes.

An enemy source indicates that these combat detachments of Air Groups are known as HONTAI, which means "main unit". The home detachments are known as ZANRYUTAI, which means "remaining units". These terms indicate the overseas detachments to be larger than the home units.

E. Type Wings (DAITAI), Squadrons (CHUTAI, BUNIAI), Sections (SHOTAI).

As indicated in Part I of this text, the DAITAI (Type Wing) exists as a unit, only when in flight. It does not exist as an administrative unit, on the ground. Thus, organizationally, the Air Group breaks down into a variable number of Squadrons, of 9 planes each.

Three Squadrons flying together as a unit are called a DAITAI. Such a Type Wing will be commanded by the senior Squadron leader present.

The Squadron, in flight, is known as a CHUTAI; as an administrative unit, on the ground, it is known as a BUNTAI. The Squadron breaks down into 3 Sections (SHOTAI) of three planes each.

As an example of the administrative break-down of an Air Group into Squadrons, the following make-up one KOKUTAI is cited:

BUNTAI #1 & #2 : Fighter squadrons (total : 22 planes).

BUNTAI #3 & #4 : Fighter maintenance unit.

BUNTAI #5 & #6 : Bomber squadrons (total : 18 planes).

BUNTAI #7 : Bomber maintenance unit.

BUNTAI #8 : Communications unit.

BUNTAI #9 & #10 : Administrative units.

It is stated that, within this KOKUTAI, the two fighter BUNTAI were treated as one unit, and the two bomber BUNTAI were treated as one unit. The total fighter unit, when in flight, was probably called a DAITAI, the same being true of the total bomber unit.

It appears that a KOKUTAI may sometimes have plane strength in reserve, in addition to the complement of its DAITAI. The above KOKUTAI had two DAITAI of 30 planes each, plus a Group reserve of 10 planes, making a total KOKUTAI strength of 70 planes.

Its interesting to note that this Air Group apparently functioned as one unit, instead of being broken up into a home detachment and a combat detachment.

The above maintenance BUNTAI break down into maintenance HAN (Platoons), of 50-60 men, each attached to one aircraft Squadron.

- III -

ARMY AIR FORCE

It is felt that naval personnel should be familiar with Japanese Army air organization, because of the increasing use of Japanese Army air units in the Pacific. Their assignment to this theater has been brought about both by a desire to afford close air support to Army ground troops in New Guinea and New Britain, and by the need to make good drastic air losses suffered in the Pacific by the naval air force.

1. Army Aviation Headquarters (RIKUGUN KOKU HOMBU).

The administration of Army aviation was reorganized in May, 1942, in order to give the Army Air Force a degree of power and autonomy not unlike that of our own A.A.F. At that time the Army Aviation Headquarters (RIKUGUN KOKU HOMBU) were set up, to be headed by a Lieutenant General (RIKUGUN CHUSHO) or a full General (RIKUGUN TAISHO). RIKUGUN means "Amy",as distinct from KAIGUN, "Navy".

The Commanding General, Army Aviation Headquarters, is directly responsible to the Emperor, instead of to the Minister of War, or the Chief of the General Staff, who are his equals in rank and who also enjoy direct access to the Emperor. These three officers constitute the High Command of the Japanese Army, the head of Army Aviation Headquarters having cognizance of Army air opera­tions, training, and materiel.

It is obvious, however, that this officer, much like the Commanding General of our own Amy Air Forces, is not in a position to exercise direct tactical command over the widespread air forces which he heads. This tactical command must rest with heads of the various Air Commands in differ­ent theaters of war.

2. Air Commands (KOKU HEIDAN) and Flying Divisions (HIKO SHIDAN).

HIKO is "flying", SHIDAN is "division", hence HIKO SHIDAN is "Flying Division". The Flying Division is the largest unit of the Japanese Army Air Service. Commanded by a Lieutenant-General, it includes anywhere from 200 to 400 planes, and the units, necessary to servicing thereof.

Seven Flying Divisions have been identified: the 1st in Japan proper, the 2nd in Manchuria, the 3rd in China, the 4th in Manchuria and the North China, the 5th in Burma and adjacent regions, the 6th in the Southwest Pacific, and the 7th in the N.E.I. Headquarters of the 5th are at Rangoon, of the 6th at Rabaul, and of the 7th at Ambon.

The 6th and 7th Flying Divisions were very recently activated. It is believed that they were organized out of units taken from other Flying Divisions for this purpose.

A Flying Division does not maintain any fixed size or composition; it may shrink or expand as the military situation requires. Air units are shifted freely from one Flying Division to an­other; the Divisions themselves are rarely moved about as units.

One step above the Flying Division is the KOKU HEIDAN. KOKU is "air", HEIDAN is "Corps”; KOKU HEIDAN is translated "Air Command". Three Air Commands have been identified, each headed by a Lieutenant General: the 1st in Japan proper, the 2nd in Manchuria, and the 3rd at Singapore.

These Air Commands are staffs, not units. They control all Army air operations within the areas under their cognizance. Thus the 1st Flying Division answers to the 1st Air Command; the 2nd, 3rd, and 4th Flying Division to the 2nd Air Command; the 5th, 6th, and 7th Flying Divisions, probably, to the 3rd Air Commands.

The Air Commands are not mobile; they are permanently established, in different theaters of war, to exercise strategic command over Army air units in those theaters. Tactical command remains with the; Flying Division, or, when that unit is too widely scattered to function as a body, with the Flying Brigade.

Units may be freely shifted about from one Air Command to another, the Command itself re­mains unaffected. Air Commands are created or abolished as the tempo and location of air opera­tions seem to require.

It is interesting to speculate on the relation between these commands of the Japanese Armyair forces and the equivalent commands of the Japanese Army ground forces.

The Japanese armies, which might be compared to Flying Divisions, are coordinated by staffs, which might be compared to the Air Commands. These staffs are: C-in-C, National Defense Forces, in Japan proper; C-in-C, Kwantung Army, in Manchuria; C-in-C, Forces in China; C-in-C, Southern Expeditionary Forces, with headquarters at Singapore. It is not certain whether the 8th Army Group, controlling ground forces in the south and southwest Pacific, with headquarters at Rabaul, answers to C-in-C, Southern Expeditionary Forces, or directly to the Army High Command in Tokyo.

It will be seen that C-in-C, National Defense Forces, corresponds to the 1st Air Command; C-in-C, Kwantung Army, and C-in-C, Forces in China, to the 2nd Air Command; and the C-in-C, South­ern Expeditionary forces, to the 3rd Air Command.

It is not known whether, in these cases, the Air Command is subordinated to the equivalent ground command, or whether each of the two commands answers individually to the Army High Command in Tokyo. In the latter case, the ground and air commanders are presumably expected to effect co­ordination on a voluntary basis. The Japanese emphasis on unity of command, and on the use of air power in support of ground operations, makes the former course more likely than the latter, however.

3. Flying Brigades (HIKODAN) and Flying Regiments (HIKO SENTAI).

The Flying Division breaks down into about 3 Flying Brigades, each with about 70-120 planes. The Flying Brigade is generally commanded by a Major General (RIKUGUN SHOSHO), though sometimes by a Colonel (RIKUGUN TAISA). It may be roughly compared to a Navy KOKUSENTAI (Air Flotilla).

HIKODAN is an abbreviation for HIKO, which means "flying", and RYODAN, which means "Brigade". The HIKODAN are very mobile, being divorced from servicing and administrative responsibilities. They are freely shifted from one Flying Division to another; thus, for example, a given Flying Brigade might fight in Burma during the dry season as part of the 5th Flying Division, and might be transferred to the NEI as part of the 7th Flying Division during the Monsoon.

A Flying Brigade breaks down into 3 Flying Regiments, each of about 27 planes. HIKO is "flying", SENTAI is "battle unit". Flying Regiments were called HIKO RENTAI before the war. RENTAI being the ground forces' term for "regiment". Lately the more dynamic term SENTAI has been substituted.

The Flying Regiments, like the Flying Brigades, tire divorced from administrative and servic­ing duties, and hence are extremely mobile. However, they generally function within the framework of the Flying Brigade - Flying Regiments are not shifted from one Brigade to another as freely as Brigades are shifted from one Flying Division to another. Flying Regiments are generally commanded by Majors (RIKUGUN SHOSA) or Lieutenant Colonels (RIKUGUN CHUSA).

A Flying Brigade does not necessarily consist of only type of aircraft, a Flying Regiment generally does.

4. Type Wings (DAITAI), Squadrons (CHUTAI), Sections (SHOTAI).

A Flying Regiment breaks down into three Squadrons (CHUTAI), of 9 planes each. The Japanese Army Squadron is the same as the Navy squadron, breaking down into three sections (SHOTAI) of three planes each. A squadron will generally be commanded by a Captain (RIKUGUN TAII). When in flight, three squadrons are termed a DAITAI. This is exclusively a tactical term.

Certain Squadrons operate independently, usually as observation units, attached to ground forces. These are termed DOKIRITSU CHUTAI (independent Squadrons).

5. Task Forces (BUTAI).

He have noted the Navy use of BUTAI, KUSHUBUTAI, and KICHI KOKU BUTAI. The Army also creates tactical air task forces - though less frequently and regularly than the Navy. Army air task forces are termed BUTAI, their size and composition will vary according to their mission. Their existence probably does not outlast the fulfillment of this mission.

6. Administrative Units: Air District Hdqts. (KOKU CHIKU SHIREIBU), Airfield Battalions (HIKOJO DAITAI), Airfield Companies (HIKOJO CHUTAl).

Scattered throughout "Greater East Asia" are Japanese Air District Headquarters. These are staffs, each of which controls all aviation ground functions (servicing and administrative) in the area under its cognizance. It will be recalled that the Flying Division is organized on a rather permanent territorial basis: it is believed that such a division will break down tactically into Flying Brigades, and administratively into Air District Headquarters.

The Flying Brigades are mobile combat aviation units; the Air District Headquarters are im­mobile ground "housekeeping" units. Both answer to the Commanding General of their parent Flying Division, who thus controls all aviation matters within the zone under his command. Comparatively little is known of the organization and content of the Air District Headquarters.

A lower administrative and servicing echelon is the HIKOJO DAITAI. HIKOJO means "airfield", DAITAI is "large unit". The Airfield Battalion is generally attached directly to a Flying Regi­ment, whose administrative and servicing functions it assumes.

On the following page is a chart, reproduced from ATIS, SHPA, Serial 159, showing the organi­zation of an Airfield Battalion, as described by an enemy source. It will be seen that the Battal­ion breaks down into a guard company, a supply company, and a servicing company, this latter con­sisting of three servicing platoons, each attached to one aircraft squadron.

The Airfield Battalion is a mobile unit. It does not necessarily move with the Flying Regi­ment, but will generally move closely after, or effect a rendezvous with, such a parent unit, as the latter will be heavily dependent on it for servicing. It is believed that an Airfield Battalion will come under cognizance of the Air District Headquarters in whose area it functions.

The HIKOJO CHUTAI, or Airfield Company, is a miniature version of the Airfield Battalion. It will be attached to squadrons operating independently or to small advanced airfields.

7. Training Units: Air Training Divisions (KYOIKU HIKO SHIDAN), Air Training Brigades (KYOIKU HIKODAN), and Air Training Regiments (KYOIKU HIKO RENTAI).

Advanced operational training is conducted by Flying Divisions - particularly those in quiet areas, such as Japan and Manchuria.

Primary and intermediate training was formerly the function of the First Flying Division, in Japan proper. Lately it is believed that this division has been relieved of primary and intermedi­ate training, so as to free it for the defense of Japan and the Kuriles. Those of its units which carried on training activities have been assigned to the newly created 51st Air Training Division, also located in Japan proper.

So far no other Air Training Division has been identified. The 51st Air Training Division breaks down into Air Training Brigades and Air Training Regiments much like any other Flying Divi­sion. The word KYOIKU, which will be noted in the above titles, means "training."

- IV -

FLYING BANK - ARMY AND NAVY

1. Officers

Officers of the Japanese Army and Nary air services have - like U.S. flyers - the same titles and badges of rank as other line officers of the service to which they belong. These titles and Insignia are reproduced on pages 15 and 16.

In the case of naval officers' collar and shoulder tab Insignia, the cherry blossoms are silver, the areas shaded In the Illustrations on page 15 are black, and the unshaded areas are gold. In the case of flying officers, the cherry blossom may be blue; In the case of air ground staff officers, it may be green. These Insignia are worn as collar tabs on blue uniforms, and as shoulder-boards on white uniforms. The cuff bands are black on blue uniforms, gold lace being used for ceremonial dress. On flying dress, officers wear a cloth patch on the left aim above the elbow, bearing a design in gold lace similar to that of the cuff bands.

In the case of the army officers' Insignia, the stars are gold, the areas shaded an page 15 are red, and the unshaded areas are gold.

It will be noted that Army and Navy Officers have the same titles of rank. The words KAIGUN ("Navy") and RIKUGUN ("Army") are prefixed to avoid confusion. In the Navy, flying officers put the term KOKU between KAIGUN and their title of rank, while air ground staff officers use the term SEIBI In the same way. Thus a KAIGUN KOKU SHOSA is a flying Lieutenant Commander, while a KAIGUN SEIBI SHOSA is a Lieutenant Commander, A-V(S).

The SHO which Is used in SHOSHO (rear Admiral), SHUSHO (Vice Admiral), and TAISHO (Admiral), means "commanding officer", and may, on occasion, be used as follows: SHOTAISHO (Commander of a SHOTAI), CHUTAISHO (Commander of a CHUTAl), and so on. This is a way of referring to the unit's C.O., without designating his actual rank.

2. Enlisted Personnel

Both Japanese air services make great use of enlisted men as pilots and as members of air­crews. Even as pilots, enlisted men outnumber officers by as much as four to one.

With respect to naval enlisted ranks, it should be noted that the HIKO SOCHO (U.S.N.: War­rant Officer) wears a sleeve cuff band, collar tabs, and shoulder hoards; the JOTO HEISO (U.S.N.: Chief Petty Officer) has three cherry blossoms on the sleeve, but no collar tabs or shoulder boards; while the other six enlisted ratings wear their Insignia on the right aim, just above the elbow.

The word HIKO, which will be noted in the titles of all eight ratings, means "flying". In the case of the ground air staff, SEIBI is substituted for HIKO in the title, and a speckle of air­plane, seen from a side view, is substituted for the solid airplane, seen from above, in their in­signia. The personnel of both the Flying and Ground Crew branches are divided into specialist categories, each category being distinguished by its own badge and title.

These categories are as follows:

1. Flying (HlKO) Branch.

A. Pilots (SOJUIN).

1. Fighter pilots (SENTOKE SOJUIN).

2. Bomber pilots (BAKUGEKI SOJUIN).

B. Non-Pilots (TEISATSUIN).

1. Observation, navigation, photography, etc. (TEISATSU).

2. Badio and gunnery (DENSHIN).

II. Ground Crew (SEIBI) Branch.

A. Ground Mechanics (SEIBIIN).

B. Armament Specialists (BEIKIIN).

C. Flying mechanics (TOJOIN), who maintain and inspect equipment in flight. These men constitute less than 5% of the ground crew branch.

In the case of Army enlisted ratings, the same use of HIKO will be noted. For the ground crews, SEIBI is substituted. Enlisted men down through the grade of corporal may act as pilots; all enlisted men may be members of aircrews. There are no U. S. Army equivalents for the HIKO GOCHO and the HIKO JOTO HEI, these terms have therefore been literally translated.

3. Illustrations

The charts showing Japanese Army and Navy flying ranks are given on the following two pages. In these charts, certain Japanese Navy enlisted titles are given in parentheses. These re­present abbreviations which are frequently used by the Japanese instead of the full title of the rank in question.

Ranks 1

Ranks 2

TABLE A, Part 1 – Japanese Naval Air Service

TABLE A, Part 2 – Japanese Army Air Service

GLOSSARY OF NAVAL ABBREVIATIONS EMPLOYED IN THIS PAPER

********

SHIPS

BB - battleship

CA - heavy cruiser

CL - light cruiser

DD - destroyer

SS - submarine

SA - submarine tender

CVS - seaplane carrier

XCVS - converted seaplane carrier

CV - aircraft carrier

ACV - Auxiliary aircraft carrier

APV - aircraft transport

PLANES

VF - fighter

VB - horizontal bomber

VB - dive bomber

VTB - torpedo plane

VOS - observation plane

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