by Mark Wlodarczyk
This essay is part of a larger work on the Japanese Nakajima Ki-43 ”Oscar” fighter airplane, soon to be published in Polish by AJ Press in the ”Monografie Lotnicze” book series. An English translation will hopefully follow soon. The ”Oscar” was the Imp. Japanese Army’s main fighter during the Pacific War and a significant aircraft in the military aviation history. Regretfully, outside of Japan, it has not yet generated the interest amongst writers and publishers it deserves. I hope this ”sneak preview” will please fellow aviation enthusiasts and modellers.
(Although the essay deals with the ”Oscar” only, it can also provide some guidance on the issue of painting and markings of most other Japanese Army aircraft of the period. – MTW)
During the operational history of the Ki-43 there was a very wide range of colours and tones, as well as painting schemes and techniques used. There was at the time no official colour reference system in Japan that would today help to recreate this colours. There are only but a few surviving aircraft or parts of aircraft. Therefore establishing any colour is only possible in the sense of well qualified guesses and logical assumptions, based on descriptions, written regulations, analysis of the few remnants and careful study of, for the most part, b/w photographs. The fact that even the existing Army Air Force painting regulations were seldom carried out to the letter doesn’t make the task easier.
Although the most recent western and Japanese sources, as well as opinions of a number of experts on the subject, have been consulted in the making of this text, all the colours given are to be understood as only typical representations of a much wider variety. It may be wise for the modeller and for the historian to bear in mind that painting of the aircraft was not one of the prime concerns in combat circumstances, which may have had an effect on the memory of the participants.
All studies of Japanese subjects are weighted with additional problems connected with cultural and linguistic differences between Japan and the western (i.e. non-Japanese) world. Much of the older Anglo-American writings on Japanese aviation contain errors and uncertainties caused by gigantic translation difficulties. Many colour notions common to us lack the exact equivalents in Japanese, and vice versa. Furthermore, there are problems within Japanese itself in transforming the spoken language to the written one, and in correctly understanding the written language of the ’40s. It’s worth mentioning that in Japan today some traditional colour names are being abandoned and replaced by words borrowed from English, mainly for practical reasons. In this context it is easy to grasp the difficulties in avoiding mistakes and errors, also in Japanese sources, for reasons other than the lack of sufficient references. It is our hope that the information in this text is appropriate within reasonable limits. We also hope that further research and discussion in this field will extend our knowledge.
The colours are given with references to the Federal Standard FS595B. The first number in the codes, depicting gloss value, is omitted and replaced with a star (*).
The wide range of colours and the seemingly pragmatic way of applying them are some of the characteristic features of the Japanese Army Air Force (JAAF) a/c. Contrary to the Navy Air Force (JNAF), the Army didn’t attach too much importance to protective painting and, for a long time, the responsibility for camouflage lay with the commanders in the field. There are two phases in the painting development of the Hayabusa: the first without camouflage or with a field-applied one and the second with a factory painted one.
All the prototypes and all the production Ki-43 Models I and II left the assembly lines in natural metal finish. The only factory painting was the Hinomaru on top and bottom wing surfaces (late in the production of Model II also on fuselage sides), black anti-glare panel on top of the fuselage from the cowling front to the end of the canopy in open position and a few small information stencils. The fabric-covered control surfaces were from the start coated with a light greenish-grey paint (FS*6314).
The first production Ki-43:s were put into action right after delivery, first over Malaya, later in other areas of the fighting. Soon a need for camouflage for a/c operating from front airstrips exposed to constant enemy attacks was evident. It may be mentioned that camouflage was up to this point not used on JAAF fighters but the Allied opposition, in spite of the early defeats, proved to be much more aggressive than the previously encountered Soviet and Chinese. In the first months of the war field-applied two tone segmented camouflage was employed, with a wavy division between colours. The colours were brown (FS*0059) and olive green (FS*4088) or dark green (FS*4094). Sometimes three-colour camouflage was used, adding a light green (probably like FS*4172). Also the use of two shades of green has been reported. These schemes were the same as used earlier on JAAF bombers and reconnaissance aircraft. It was painted in a reasonably accurate fashion on all the upper and side surfaces of the a/c, sometimes also on the spinners.
There is no evidence of any standard schemes for the colour patterns, such as those in the RAF. The few existing photos showing topsides of the wings can therefore only serve as examples of the variety. It is known, however, that JAAF recomended for the schemes to be different from the ones observed on enemy a/c. Soon a more uniform, one-colour, dark-green, olive-green or brown camouflage started to appear more frequently, although the multicoloured schemes continued to be in use for a long time. From the spring of 1942 the painting schemes also started to vary a great deal, from thorough covering of all the upper and side surfaces to sparse, irregular blotches or streaks on the top sides with the bare metal shining through. The camouflage was painted all around the cowlings and around wing and horizontal stabiliser leading edges, as well as on landing gear covers. The black anti-glare panels were most often not overpainted and the undersurfaces were left in natural metal.
Painting techniques varied with local conditions and time available, from spraying to hand painting using wide brushes. The paints applied in such a way looked for the most part semi-matte or matte. The lack of preparatory painting and the humid, tropical climate caused rapid weathering and peel-off effects. Many photographs showing a/c wearing seemingly blotchy or hastily applied camouflage are really illustrations of deteriorated paintwork. The choice of painting scheme depended on the taste of the local commander or even ground personnel and on paint availability, including use of captured Allied paints, rather than on any JAAF recommendations. Most of the Sentais probably did strive for a uniform look for their a/c, there is however plenty of evidence for the contrary under stressed combat conditions.
Field camouflage was used only on a/c in front line service. Therefore all the Mod.I and II based in Japan or elsewhere far from the front retained the bare metal finish. There is also rich evidence of unpainted machines used by the front units throughout the war.
The use of factory camouflage applied before delivery to the JAAF began with the Ki-43 Mod.III  . All the undersurfaces were painted in light greenish-grey (FS*6357), all the upper and side surfaces in dark brown-green or brown-olive (FS*0118 and FS*4088 may serve as typical). According to some sources the black antiglare panel was no longer applied. In the factory scheme the dark upper colour was still painted around the cowlings but not around leading edges or on the landing gear covers any more. The paints were glossy when applied although not as shiny as some modern synthetic paints. The high amount of cellulose, climatic conditions and lack of proper care in combat environment all contributed to rapid fading and weathering. The surfaces remained unprimed with the resulting poor adherence of the paintwork.
The dark blue shade attributed to the Ki-43 of the 20th Sentai, as well as Mitsubishi Ki-51 of the 49th Independent Chutai deserve a special note. The fact that both units were based on Tainan (Taiwan) late in the war, with the resultant frequent over-water missions, is sometimes used as an argument for the credibility of that colour. Apart from the questionable logic of such reasoning, there is no reliable information whatever of the use of blue, factory or field-wise, as top colour in any other circumstances. Although attractive to modellers, we believe the shade was rather an effect of weathering and chalking-out of dark-green paint containing blue pigment.
Propellers, spinners, undercarriage, information signs
Both propeller faces and spinners of the Ki-43 I were left in an unpainted, polished bare metal finish. Rear sides of the prop blades were black. Some sources state that the spinners were coated with red-brown primer from very early on but it is more likely that the dark colour was part of the field camouflage. A red or brown 50mm wide warning stripe was painted on each prop face 50mm from the end. There was also a small black factory stencil near the root of the blades. From the Model II on, the spinners as well as both sides of the blades were red-brown (FS*0109 or FS*0111). The warning stripe and the factory stencil became yellow. On the late production Model II:s the warning stripe was in turn divided into three equal small stripes yellow-white-yellow. Finally on the Mod.III the entire tips of the blades were yellow, this time on both sides. Although fairly well documented, these phases in propeller painting can not be used to distinguish between the different models.
The undercarriage legs and other small exterior parts were normally not painted, though it is possible they received a coat of light grey with the introduction of the painting of the rest of the undersurfaces.
In comparison with many other JAAF a/c, the Ki-43 carried surprisingly few information and warning stencils. A small black factory serial number was painted on the rear of the port fuselage side under the stabiliser, usually repeated on the landing gear covers. A small, probably red jacking point sign was sometimes painted low just in front of it, on both fuselage sides. Also the covers of the wing fuel tanks were red. Black walkways were usually painted near the root of both wings, sometimes on the port side only.
The position lights, located on the wing tips, were coloured red on the port side and greenish-blue or green on the starboard. The clear tail light was inserted into the upper part of the vertical stabiliser.
National insignia and other ID markings
The Japanese national insignia Hinomaru (Hi-no-maru = ”the sign of the sun”) was used in both air services from the early ’20s in the six standard positions: on lower and upper sides of both wings and on both sides of the fuselage. In the JNAF this remained unchanged throughout the war. In the JAAF however, the fuselage Hinomaru was abandoned around 1937-38 and only the four wing insignias were carried. The reason for this change is not known but it occurred at the time when the hostilities with China escalated to a full scale war and it has been suggested may have been an attempt to visually distinguish JAAF aircraft from those of the Navy in combat zones, for one reason or another. In any case, the use of all six positions was reinstated around February 1942 but until the end Army a/c without fuselage Hinomaru were fairly frequent. The colour of the Hinomaru used in aviation, as well as in other contexts, was simply bright red, such as FS*1086. In time, when exposed to the elements, it changed in hue and deteriorated, losing in intensity and becoming rusty-pinkish brown in tone (FS*1328), at least on the upper and side surfaces.
Thus in the beginning only four wing Hinomaru were painted on the Ki-43. It had a diameter of 1,1 – 1.2m (¾ of the wing chord) and its centre was located 1,5m from the wingtips. In some cases the insignia on the wing undersides were painted much closer to the fuselage (2,5m from wingtips). The centre was located midway on the wing chord, ailerons included.
Factory-applied Hinomaru appeared on the fuselage some time during the production of Mod.II. Its centre was located 3,6m from the rear of the a/c (i.e. 4/10 of the length), roughly in the middle of the vertical section, and had a diameter of 0,7m. The wing Hinomaru from Mod.II onwards changed to 1,4m in diameter, its centre located 2,1m from the wing tips (the wing span being shorter than on Mod.I!). In other words the distance between the wing tip and the outer edge of the Hinomaru was equal to the diameter of the Hinomaru itself, a rather frequent rule on many JAAF a/c. These positions and sizes of the Hinomaru remained unchanged after the introduction of factory camouflage.
Whenever field camouflage was applied the factory painted Hinomaru was retained, its finish sustaining less deterioration than the surroundings. Sometimes a small unpainted ring was left around the insignia creating a halo effect. Also, from the early spring of 1942, many aircraft received field painted Hinomaru on the fuselage. Its size and location varied depending on the Sentai or even Chutai but it was generally smaller than the later factory scheme.
In July 1943 the Joint Air HQ (Koku Hombu) issued a directive setting the rules of painting of all military a/c, aiming at uniforming the appearance of a/c of both air services and giving official status to some painting and marking procedures already established at lower levels in the field. The directives included the painting of yellow friend-or-foe identification strips (ID strips) on wing leading edges, from wing root to half the length of each wing, measured from the a/c centre. FS*3538 may be considered typical although different shades, from pale- to orange-yellow were probably quite frequent. Field-applied ID strips were common from the summer of 1942  . Another directive was the white outline to all upper and fuselage Hinomaru. Its width was to be 75mm and it was to be added to the diameter of the Hinomaru, regardless of its size. Not unlike many other air arms, but in some contrast to the more rigorous JNAF, this recommendation was executed rather casually by the JAAF, sometimes depending on the a/c type. On the Ki-43 factory or field painted outlines to fuselage Hinomaru were fairly common but there is little evidence of their having been applied to the wings as a rule. With the introduction of factory camouflage on Mod.III the white outlines were officially abandoned, but many a/c seem to have received them after all.
From mid-1942 on, the aircraft of first line units based in Japan usually received a wide white band painted around the wings and fuselage beneath the Hinomaru, the so called ”Home Defence Bandage”, for patriotic as well as ground-recognition reasons. It was normally 0,2m wider than the Hinomaru. It was used rather consistently, particularly in the late period of the war  , but new Army a/c delivered in 1945 no longer received the ”bandages”.
Late in the ’30s narrow white bands around the aft fuselage, right in front of the stabiliser, started to appear as another distinctive marking of JAAF a/c. The name of ”combat stripe” has become common in many sources, as distinguishing first line service a/c from trainers, transports, prototypes and others. It is difficult to find any convincing proof of such a purpose for the stripe in Japanese references but it can be observed that its introduction coincided with the abandonment of fuselage Hinomaru and that after its reinstatement the use of the white stripe was gradually phased out. Some sources suggest the fuselage stripes were actually IFF markings and the appearance varied with the combat zone, New Guinea based a/c sporting red stripes with white outlines instead. Eventually, the stripe was very common on the Ki-43, particularly in the early years.
The presentation inscriptions (Hokoku or Aikoku inscriptions), used on a/c funded with private or corporate finance, were not as common with the JAAF as with its Naval rival. They were painted in small, black, 50mm high characters (on a small yellow stripe in case of camouflaged a/c) on both sides of the rear fuselage. They consisted of the Japanese kanji Ho-Koku Dai or Ai-Koku Dai, the donation number and, in brackets, the name of the funder. The Ki-43s of the puppet Manchukuo (Manchurian) AF are worth special note. They were marked with national insignia on the wings only, of the same size and shape as the Hinomaru but in the Manchurian colours, and with huge patriotic inscriptions along the fuselage sides that were individual for each a/c.
Most interior surfaces of the Ki-43, including wheel wells or inside the flaps, were covered with clear protective lacquer. Sometimes, but not always, some blue or blue-green pigment was added to the lacquer, simply as a control measure, thus creating a characteristic metallic effect caused by the natural metal shining through. This painting procedure is referred to as aodake or aodake iro. Late in the production this type of protective painting was all but dispensed with.
The cockpit interior, including the instrument board and seat, were additionally coated with some interior colour, such as green-olive (FS*4255) or grey-green (FS*4226). Also the use of khaki-brown (FS*3448) and black instrument panels are mentioned, especially on later models. The fuselage areas under the canopy were black. Other instruments and subassemblies in the cockpit were pre-painted black or dark-green. The knobs of the landing gear and emergency levers were probably red, throttle and pitch control yellow, the control column black or dark-green, but there is no evidence of systematic colour coding of controls. It can be assumed that from 1944 on, apart from the instrument board and some elementary anti-glare painting, all protective coating was less cared for and the cockpits were largely unpainted.
Practically throughout the war, the basic unit of the JAAF was the Sentai (= group, often inadequately referred to as a regiment). It was divided into three, very seldom four, Chutai (squadron), which in turn consisted of three to four Shotai (flight) of usually three a/c each. There were also some a/c of the Sentai Headquarters (Sentai Hombu) and, in normal conditions, some reserve a/c, normally up to 1/3 of the regular strength. The only official name given to a Sentai was its consecutive number. Similar numbers were given also to field- training or temporary units, independent Chutais, etc., and it possessed no other significance or coding. Some of the Sentais took up unofficial names based on local tradition or special achievements.
Flight schools often carried the names of their home-fields. Each unit decided upon a symbol to be carried as a recognition on the vertical stabilisers or, more seldom, on the rear fuselage. Thus evolved a very colourful system of unit heraldry, unlike any other air force of the war and deserving a book of its own. The symbols were for the most part based on the unit number expressed in Arabic numerals, but sometimes also kanji or even roman numbers, and transformed into graphic figures of various forms, from simple to very intricate, almost riddle-like designs. Sometimes old Japanese heraldry or local geography was used instead of numerals and, in the case of unit names, stylised kana or kanji. Those symbols did not always remain unchanged during a unit’s service history, there are examples of up to five different designs for the same unit over four years’ time.
Late in the war many new temporary, irregular or special attack (suicide) units were formed, often receiving new, colourful markings. These are to be seen more as morale-boosters, rather than particular unit markings. However, many simple, almost unmarked a/c were not unusual.
Command & tactical markings
The most used form of distinction between the Chutais was the painting of the Sentai symbol in different colours. The popular coding system was: white for the 1st Chutai, red for the 2nd, yellow for the 3rd, green for the 4th (if there was one) and blue for Sentai Hombu. Some Sentai used a different order of colours, some didn’t use colour coding at all. Very often spinners and, rarely, cowling fronts were painted in the Chutai colours and sometimes this replaced the colour coding of the tail marks. Another system, used primarily in the early years, was the use of additional stripes on the tail or aft of the cockpit in Chutai colours. The number of stripes could denote the Shotai. The markings of the Ki-43 equipped 1st Sentai serve as an example of this fully developed system, the combinations of stripes in different numbers, positions and colours reaching down to individual a/c of each Shotai. The use of such complicated markings was largely abandoned after 1942, remaining in practice only with the flying schools.
The a/c of the commanders of various sub-units were marked with additional, broader, straight or oblique bands in different colours painted around the rear of the fuselage, aft of the cockpit or on the wings. At the top of this system was the a/c of the Sentai commander, who sometimes used the blue HQ colour or all the Chutai colours at once. Also this system became much simpler or was abandoned late in the war.
Individual a/c numbers, usually in Arabic numerals, were quite common on JAAF aircraft, painted mostly on the rudder, often repeated on gear covers and under the cowlings. The numbers were often simply repetitions of the last two or three numerals of the serial number, not consecutive within the units and, although sometimes large in size, lacked any tactical or Chutai-denoting purpose. During the China conflict many units used hiragana characters, arranged in a way possibly denoting sequence, instead of Arabic numbers. The habit seems to have been abandoned later and there is no evidence of it in connection witht the Ki-43.
The JAAF was not as unselfish in relation to individual victories as the JNAF, yet personal ”kill” marks were quite rare on Army a/c and in the case of the Ki-43 almost non-existent. In the very few exceptions simple circles or stars were painted on the port side of the fuselage or on the rudder.
More frequent were individual pilot markings such as small initials, patriotic messages and even dedications to fiancées, painted in one or more kanji. Certainly, almost all personal markings were reserved for commanders or other distinguished pilots, as the majority of the airmen were not assigned personal aircraft.
In the JAAF there are also examples of Sentai or Chutai commanders flying personalised a/c with their own tail symbols that differed from the ones used regularly by the unit and the existence of such Ki-43s cannot be excluded.
 The Mod.III, as well as the Mod.IIb, was manufactured entirely by Tachikawa, while some Mod.IIa were made by the Rikugun factory. This didn’t seem to have affected painting procedures.
 In the JNAF the yellow ID bands appeared first in Dec.42
 It’s interesting to note that in the same period the JNAF, also involved in the defence of Japan, was dispensing with the white outlines and painting out the existing ones for low-visibility reasons!
[box]Many Thanks to James Lansdale for research pieces & comments and to Gavin Johns and Douglas Carrick for editorial assistance.[/box]
This article was originally published in IPMS Stockholm Magazine in February 1997.