Friday 20 February 2009

Ki-43 III Ko Colours ~ Part 3

The splendid box art for the 1964 Tamiya 1/50th scale Ki-43 III Ko depicting an aircraft of the 48th Sentai over China, is ambiguous in appearing to show a slightly olive green version of ohryoku 7 go shoku with natural metal undersurfaces. The instructions, however, are interesting in that they suggest that the upper surfaces were "brown (just like olive drab)" and that the under surfaces were "The same as that for upper surfaces excepting that it has been lightened with white."  This description exactly conforms to the recollections of Mr Shimoune.

Although the study is ongoing the following paint colours have been identified as being applied to JAAF drop tanks:-

1. An unidentified neutral grey - for which the closest FS value is 36293 @ 2.13 (it is slightly too blue). This appears to be the colour of the drop tanks on the aircraft in the colour photograph posted below.

2. A pale blue-green, JAAF paint standard # 17 'Tan Sei Shoku' - for which the closest FS value is 25352 @ 2.25, a good match.

3. The yellowish green colour # 29 'Ki midori iro' - for which the closest FS value is 34151 @ 2.15, not quite yellow enough. This colour was also used for cockpit interiors.

4. The olive drab #7 'Ohryoku nana-go shoku' - also used for top surface camouflage and interiors, the approximate FS equivalents to which are 33070/34088. The swatch included above is gradiated from left to right to show the brown to green ends of the colour range for this paint.

5. Yellow - which is presumed to be the standard orange yellow in use for IFF strips and trainers (q.v. Army Trainers) although a Ki-84 Hayate tank is cited to be in a yellow colour of approx FS 33655 to 33538.

Image credits: Box art & instruction sheet  © Tamiya  1964; Rendered colour swatches © Straggler 2009

Thursday 19 February 2009

Ki-43 III Ko Colours ~ Part 2

The colour value derived from an original swatch prepared by Mr Noboru Shimoune to illustrate the Ki-43 III Ko upper surface colour is Munsell 7.5 Y 3/1.5. The closest FS value to this is 33070 @ 2.49, which is just a little lighter. The RAL colour 6014 Gelboliv (Yellow olive) is slightly closer @ 2.36, but is a little darker. The colour is within the range for the JAAF Standard Ohryoku 7 go shoku which became colour standard 1-1 in the joint Army-Navy document 8609 of February 1945. 

This top surface olive-drab colour was also associated with the Ki-54, Ki-74 and Ki-94.

The swatch for the propeller colour is Munsell 5 GY 3.5/2.3 and the closest FS value is 34092 @ 2.14, which is just a little greener and not quite grey enough. Previously this colour was visually matched to FS 24172 for a 1/72nd scale model, but that is a lighter shade (the DE2000 difference calculation between 34092 and 24172 being 10.2). 

The under surface colour was visually matched to FS 36405 from a piece of extant stabilisor taken from a 64th Sentai Ki-43 III Ko in Malaya. This is a creamy "stone" colour, the closest Munsell value to which is 5 Y 7/2 @ 2.16. The top surface of this piece was visually matched to FS 34088. Mixing the upper surface colour 34088 with white results in an almost exactly similar colour to 36405.

From Mr Shimoune's article I understand the interior colour to have been the same as the top surface olive drab, which was in accordance with the Army Aircraft painting regulations (Rikugun kokuki tosou kitei) of 15th June 1943. However, Mr Kenichi Oshimo, the chief designer for the Ki-43 III recalled that the interior was painted with green or grey-green paints similar in appearance to FS 34128 and 34159 respectively. In the colour photograph the rear decking area under the canopy does not appear to be black but rather a dull olive green or olive drab colour.

"Nohryoku- shoku" as referred to in Mr Shimoune's article relates to IJA Green (Mr Color #16), Dark Green (Nakajima) (Mr Color #129) or Dark Green (Kawasaki) (Mr Color #130). The first kanji "noh" may be translated as "strong" or "dense" so "deep green" may be a suitable description.

"Anryoku-shoku" as referred to in the article relates to IJN Green (Mr Color #15) or Dark Green (Mitsubishi) (Mr Color #124). The first kanji "an" may be translated as "dark" so "dark green" may be a suitable description.

The two colours in the original JAAF standards that also use these descriptions are #22 'Noh Ryoku Shoku' and #26 'An Ryoku Shoku', but unfortunately the precise nature of the appearance of these colours is not known. 

Very special thanks to Isamu Marahashi for kindly clarifying these colour descriptions.

Image credits: Ki-43 III Ko schematic © William Leyh & Nick Millman 2005; colour swatch renderings © Straggler 2009

Tuesday 17 February 2009

Ki-43 III Ko Colours ~ Part I

Ta.Gucci has posted an interesting profile at his blog of a well known Hayabusa Ki-43 III Ko photographed in colour at Kimpo, Korea, just after the war*. The post includes, via Maru-san, a fascinating report on the factory painting of the III Ko aircraft by Mr Noburo Shimoune who was involved in manufacturing the Hayabusa at Tachikawa Hikoki. Isamu Maruhashi has very kindly translated this interesting and useful post into English for us.

"The 1968 Koku Joho magazine supplement scale model guide 'Japanese Aircraft of WWII' has a section written by Mr Noboru Shimoune who was involved in manufacturing Hayabusas for Tachikawa Hikoki. The article reads as follows:-

"The Model 3 Koh which appeared at the end of 1944 was painted in the same manner as the previous Model 2 Kai in that all aircraft had both their top and bottom surfaces painted at the factory. Conventional magazines and scale model instructions often state that these aircraft were not painted when shipped and that they were painted with Anryoku-shoku blotches in the field, but this is total nonsense. The single-exhaust pipe Model 2 Kai was initially shipped unpainted to units and painted in the field, so maybe they are being mistaken for Model 3s.

"The top surface of Model 3s were painted a dark Tsuchi-iro (earth or clay colour). It was a brownish colour rather than a greenish colour. (For whatever reason, people keep insisting that the colours were Nohryoku as if that's the only colour they can contemplate). I was familiar with the sight of unpainted Type 1 fighters, so I was appalled at the dirty colour that they had painted them. If we go by the colour of the plastics used in molding scale models, the colour was close to that of the plastic used to make the Monogram P-40s and P-51Bs (although it was a little lighter in tone).

"(This doesn't have any direct relation to this story, but in the fall of 1944 the Sentai of new Hiryu Type 4 Heavy Bombers at Tachikawa Base were also painted a colour similar to the Type 1 Model 3 Fighter. This colour was close to Pactra Olive Drab. The underside was painted black).

"Getting back to the Type 1 Fighter, I want to say that the underside colour was gray, but it was not Nezumi-iro (rat or mouse colour). Rather it was a colour similar to the top colour but lightened with white. This was totally flat colour. The boundary of the two colours were spray painted and the border slightly soft. None of the airframes were painted with the black anti-glare paint that was used on unpainted aircraft. The headrest inside the canopy was painted black, the cap of the methanol tank behind the headrest was painted silver, and all other colours were the top surface colour. The seat was unpainted duraluminum and an anti-corrosive was not applied to the interior. None of the Hinomarus had white outlines. However there were some airframes that had Hinomarus inside white bands on both the wings and fuselages. The propellers and spinners were painted Ebi-cha-iro (red brown colour), and they were the same as other airframes in that there was one yellow stripe at the tips of the propeller blades, but near the end of the war the propellers were painted Nohryoku-shoku, and the tips were painted yellow like the American planes, (both in front and back). The Model 3 Otsu airframes were equipped with these Nohryoku-shoku propellers.

"On the top of the left wing root a black sandpaper-like anti-slip material was applied along the fuselage, and pilots stepped on this when boarding their planes. The fuselages did not have any steps, so one piece of green rope was hung down from the cockpit, and the pilots grabbed those ropes when boarding their fighters. The landing gear wells were totally painted in blue anti-corrosive primer. The commercially available Humbrol metallic blue is a close colour. The navigation lights that stuck out up and down from the ends of the wings were naturally red and green (some were blue), but when they were not lit they looked black. The tail light was white. The antenna pole was Ebi-cha-iro."

"This account shows that what we thought from colour photographs to have been an overall "gray" colour was actually - (!) And then from the latter half of 1944 the top sides of the aircraft were painted "Ohryoku 7-go Shoku" directly in the factory. And surprisingly the undersides were a cafe-au-lait like colour in which the Ohryoku 7-go Shoku was mixed with white. An overall flat colour. The author also mentions his impression ("dirty colour") and I can certainly sympathise. When the propellers had one yellow line they were painted the aforementioned dark brown. When the tips were totally yellow, the propellers were painted "Nohryoku-shoku". In most cases the propellers of aircraft in use were Hamilton-type propellers made by Sumitomo Metal, and since it can be assumed that there were no individual differences in the propellers, this difference in colour might have been a way of warning maintenance personnel that these different coloured propellers were not interchangeable.

"We had not filled in the fuselage Hinomarus, but thanks to Maru-san's description we have added them. Since it was the second half of the war, not having a fuselage Hinomaru was inconceivable, so the fuselage in the photograph must have been left abandoned for so long that the Hinomaru could not be seen because of weathering and fading of the colours.

"In any case I would like to thank Maru-san for helping us to understand so much about them."

Whew! That's enough to be going on with I think. We'll take a closer look at the colours mentioned here in Part II.

With very grateful thanks to Maru-san and Ta.Gucci for bringing back this fascinating information from the past and especially to Isamu Marahashi for allowing us to read it in English without the puzzling confusion of a machine translation! 

*Image credit: Pacific War Eagles in Original Colour, © Jeffrey L Ethell, 1997