Monday, 31 August 2009

Aichi M6A1 Seiran Colours

This schematic on the subject of Aichi M6A1 Seiran (Navy Experimental 17-Shi Special Attack Aeroplane) colours was prepared in response to a private request and may be shared here. The colours are as measured and recorded on the surviving NASM example by Robert C Mikesh and documented in his article 'Japanese Aircraft Colors at NASM' which appeared in Vol.3 No.1 of the Asahi Journal and also in the Seiran feature of his book 'Japanese Aircraft Interiors 1940-1945' (Monogram Aviation Publications, 2000).

Regarding the interior colours Mr Mikesh noted that they predominantly approximated the Thorpe identified colour N2 which has been matched to Munsell value 10 G 3/2 (see Thorpe Colour Table).

In his monograph on this type in the Monogram Close-Up series published as #13 'Aichi M6A1 Seiran' (Monogram Aviation Publications, 1975), Mr Mikesh identified the upper surfaces as being 'Dark Green' Munsell 10G 3/2 with the lower surfaces as 'Light Grey' Munsell N 7.5 and the interior as 'Olive Green' Munsell 10 Y 4/4. The latter value Munsell 10 Y 4/4 is the colour identified as N5 'Light Olive Green' by Thorpe.

Mr Mikesh also authored two earlier booklets on the subject of Japanese interior colours in the Monogram Close-Up series as #14 and #15 respectively, 'Japanese Cockpit Interiors', Parts 1 and 2, (Monogram Aviation Publications, 1976). In this publication he identifies Munsell 10 G 3/2 as 'Exterior Navy Green' and notes that there is no close FS 595b equivalent to it. The closest is actually 34058 @ 3.99 but it is too blueish in appearance (a value of 2.0 or less equals a close match).

An excellent account of the last operational use of Seiran may be found in 'I-400 Japan's Secret Aircraft-Carrying Submarine - Objective Panama Canal' by Henry Sakaida, Gary Nila and Koji Takaki (Hikoki Publications, 2006). The type is also covered in Ryusuke Ishiguru and Tadeusz Januszewski's superb 'Japanese Special Attack Aircraft & Flying Bombs' (Mushroom Model Publications, 2009) reviewed here.

Image credits: Seiran colour photograph Mark H Brown/USAFA via author; Rendered colour chips © 2009 Straggler incorporating original Kariki 117 paint standard plates.

Saturday, 29 August 2009

Useful Colours ~ Army Interiors Part One

"A little learning is a dangerous thing" said Alexander Pope. Well in modelling terms it is probably not dangerous - perhaps just misleading and rather irritating. Perhaps for modelling purposes Amos Bronson Alcott is more succinct: "To be ignorant of one's ignorance is the malady of the ignorant". Mr Alcott's observation is vindicated online on an almost daily basis and it often seems that those most afflicted with the malady are the most persistent imparters of opinion and information.

One of the most prevalent outcomes of "a little learning" is the dissemination of information in diluted or misunderstand forms which then become modelling conventions. There really does need to be a distinction drawn between the freedom to paint one's model whatever one likes and the sometimes unstated implication that the choice represents an outcome of research intended to impart "a little learning" to others. By such dubious means we have a generalised belief (reinforced by hobby paint companies) of aotake as a metallic blue-green paint applied in all Japanese aircraft cockpits and Luftwaffe sandgelb used by Kawasaki to paint the interiors of all their aircraft.

In Army form 'aotake' was introduced as a translucent dark blue primer for the interior of aircraft by the Army aircraft painting regulations of 3rd March 1932 (that is the Army painting regulations - once more - the Army painting regulations). It was not metallic per se but the application of the clear blue to bare metal surfaces no doubt gave (and gives) that impression. On 5th February 1936 the regulations were revised and the use of aotake (青竹色 - literally blue green bamboo colour - or sometimes written as 淡青色透明 - literally thin, translucent, light blue colour) was replaced by a dark greyish blue opaque primer paint which became colour standard #3 Hairanshoku or Hai-Ai-iro (灰藍色 literally ash indigo colour e.g. a greyish blue) in the Army colour standards. In practice this new paint was usually applied to internal crew areas whilst 'aotake' continued to be applied to other internal areas. Was #13 Ao iro ( 青色 - blue colour) also applied to some cockpits, either in error or expediency? Maybe.

There are two clues to the appearance of this colour standard. Firstly the actual Hess-Ives values used to measure the authorised range of hue in the procurement of Army paint supplies and secondly a pre-war French colour card which illustrates the colour and explains its use. Was there a connection between the French bleu nuit (night blue) interior colour and the Japanese interior colour? Perhaps. There is also another thing to bear in mind which is the distinction to be drawn between the colour standard and the actual paint supplied and applied. The two are not invariably the same. The promulgated colour standard displayed a variable and authorised range against which the paint suppliers (or more usually aircraft manufacturers) attempted to match. This distinction does seem to be misunderstood or perhaps under-appreciated.

In Methuen terms the median standard colour is a dark greyish blue between 23 E-F 5. The closest standard Munsell notations are between 2.5 PB 3/2 @ 2.98 and 2.5 PB 3/4 @ 2.40. The closest FS 595b value is 25053 @ 3.61 (but too blue), but 26118/36118 @ 7.02 (too grey) is often cited and indeed may provide a better scale impression although it is not quite blue enough. (A comparison value of 2.0 or less equals a close match). Ken Glass kindly advises that a reasonable out of the bottle match is Pollyscale RLM 24 Blau but it may need to be lightened with white and/or toned down with grey to match the swatches. 

The survival of badly weathered remnants of this paint in cockpits can give rise to a misidentification as aotake, but in practice diluted #3 spray or brush applied is not dissimilar in appearance. Aircraft interiors known to have been painted to #3 standard are Type 91, Ki-27, Ki-21, Ki-36, Ki-43, Ki-44 and Ki-48. Ichiro Hasegawa described the interior of a Ki-55 ('Ida') as having been painted in two colours, one being the bluish grey and the other a yellowish grey-green (the latter colur will be examined in Part 2). He also described the interior of both the Ki-21 ('Sally') and Ki-27 ('Nate') as being painted in this bluish grey which created a "gloomy impression", even the gunners mats being painted the same colour.The use of this colour continued until the introduction of new requirements on 15th June 1943 - of which more anon.

One of the aspects of the study of Japanese aircraft that continues to surprise me is the inability or perhaps unwillingness of some to reconcile the known (and published) Army colour standards with the extant appearance of paint on artifacts. It sometimes seems as though an element of being in denial exists, as though somehow the Army colour standards are not real and an opinion about a 65 year old fragment of paint without antecedence or provenance is more reliable. Hopefully one day we shall be able to move on from a quasi-religious veneration of the paint fragments to a broader and more equivocal appreciation of all the evidence.

Once this mini-series on interior colours is complete I intend to make it available as a pdf with appropriate hobby paint mixes which we are working on.

Image credits:- Ki-21 crew © 1942 Front Magazine; Colour chips © 2009 Straggler

Tuesday, 18 August 2009

Battle Over The Homeland 1946

Two of the many things I like about Ronnie Olsthoorn's (aka "Skyraider3d") stunning aviation art is the way he manages to convey a real sense of altitude and terrific movement in the scenes. This image of Mansyu Ki-98 pushers of the 4th Hiko Sentai intercepting flying wings over Japan in late 1946 was created for the cover of Edwin M Dyer III's forthcoming book 'Japanese Secret Projects - Experimental Aircraft of the IJA and IJN 1939-1945' to be published by Midland to be published later this year (I hope!).

It is a great pleasure and privilege to be able to showcase both the art and the book here at Aviation of Japan. One to watch out for and Midland Publishing have a winner in their 'Secret Projects' series not least for the exceptionally imaginative and inspiring cover art.

More wonderful images may be found in Ronnie's galleries here and here and prints of his superb aviation art may be obtained here.

Now all we need is for one of the mainstream Japanese kit companies to "do a Revell" and bring some more of the exotic aircraft from 'Japan 1946' to the 1/72nd scale shelves!

Image credit:- © 2009 Ronnie Olsthoorn & Midland Publishing

Monday, 17 August 2009

New Limited Edition Ki-10 Decals!

In close collaboration with Ken Glass, Empire City Decals (ECD) has produced a unique set of decals available in both 1/72nd and 1/48th scales for the Kawasaki Ki-10-II under the new JNAF/JAAF Research logo. The unit markings for three aircraft include a correctly proportioned fuselage eagle motif for the 2nd Chutai of the 2nd Hiko Daitai in China, 1938. The decals have been reproduced by Draw Decal as a very limited release available solely from Ken Glass but ECD will have a small number for sale at the IPMS-USA Nats in Columbus, OH, USA.

The other markings on this sheet include the tail insignia for the 1st Chutai of the 33rd Hiko Sentai in China and the tail insignia for an aircraft of the 3rd Chutai, 9th Hiko Sentai. All three aircraft are in the overall hairyokushoku (grey green) colour scheme. Please note that the sheet does not include Hinomaru which must come from the kit to be used.

Recent 1/72nd kits of this enigmatic JAAF biplane fighter include a mainstream injection molded kit available from ICM and a limited edition kit available from Avis. In 1/48th there is the superb kit by Fine Molds, available in three versions.

Image credit: © 2009 Empire City Decals & Ken Glass

Thursday, 13 August 2009

Painting Into A Corner ~ Part 1

When it comes to colour research actual airframe artifacts with original paint still adhering to them are seductive, like colour photographs. They represent a tangible link to the original aircraft - a tangible link to the past - and can be held in the hand and viewed at different angles and under different light. It is wholly understandable that they play such a significant part in our perception of what these famous aircraft really looked like.

Unfortunately, as with colour photographs, they may not be what they seem. 1940's paint technology was very different from modern paint technology and in Japan the use of synthetic or organic substitutes for scarce mineral pigments and additives took its toll on the stability and colourfastness of the predominantly nitrocellulose based paints in use. The contemporaneous problem with colour shift has been mentioned by a leading Japanese researcher who has written:-

"When gray is mixed with little yellow, it turns to light greenish gray. This is a very simple truth. The same thing is now being discussed about the Luftwaffe Sky like RLM76.

What I said is very simple. J3 was the color defined as an official surface color. I do not deny any sample of khaki or hairyoku or ameiro. I think there were those kinds of colors even in '42 or '43. What I said is there could have been many kinds of gray because that gray was changing very rapidly.

There is no official document to confirm it but some documents imply that paint was improved mid '43. This might support (the idea) that gray on (A6)M5 samples is much more like gray than those on (A6)M2, (A6)M3 because the paint was more durable against color changing. As I said, this is not confirmed.

Some serious Japanese researchers whom I know have opinion like below:-

1. There were a variety of grays including Hairyoku, Khaki, ameiro and etc. No doubt about it.

2. There are two possibilities.
a) Different color was used for each sample.
b) Color change (of applied paint)

3. From Japanese documents:-
a) There is no statement found so far that any other color than J3 was used.
b) The problem of changing color of clear paint (binder) is reported.

4. Right now, the possibility of color change is slightly stronger than that of using different color.

I admit we cannot reach a firm conclusion. However, we can not discuss color based only on samples and color chips any more. Before, when people said about color change, there were not enough supporting documents but today, there are. We cannot rule out the possibility of color change. Important thing is that many researchers admit there could be many kinds of colors. They are now try to find out why it happened. If some one picks up one sample and says it is Tsuchi-iro because it matches the color chip in the standard, unfortunately it will not be convincing at all to those Japanese researchers today."

Even the most advanced polyurethane paints of today are seldom guaranteed to a colour shift of less than a Delta-E value of 5 over a 40 year period. To put that into perspective it represents approximately the difference between Thorpe's N9 and FS 34201 at 5.40. The latter value has often been cited as a close match to early Zero paint samples. The plate above shows these two colours together. It is quite possible therefore that a 65 year old paint sample that is now matched to FS 34201 originally looked more like grey. We will look at the subject of grey and more specifically J3 in a subsequent post.

The wartime paints were far less advanced than the modern paints and have endured 65-70 years of UV exposure, chemical change and/or thermal ageing. Nitrocellulose paints of this era would typically exhibit significant colour shift and degradation, even when carefully preserved from UV exposure, over a period of only 5-10 years. Leading paint technology experts believe that after 50 years the pigment residues, even on these carefully preserved examples, would be "useless for attempting to discern their original colours".

The promotion of the current appearance of these artifacts as literal evidence for the paint colours in use in 1941-45, without allowing for or mentioning colour shift and degradation and to the exclusion of all other evidence is a flawed and misleading approach. From a purely historical research perspective it could be viewed as irresponsible.

Beyond the current appearance of the paint samples but related to it is the colour science that determines how the paint surface is measured and matched using recognised colour standards. This seems quite straightforward but it is not. Some colour occupies a subtle colour space and only very small shifts are required to result in a very different appearance to the surface. Recently a claim was made that the current colour of a particular artifact matched the appearance of the undersurface colour on an aircraft of the same type seen in a wartime colour photograph (in other words the colour photograph corroborated the current appearance of the colour in the artifact). However, much to the annoyance of the claimant it was possible to demonstrate using colour science that his claim was poppycock. The colour in the photograph did not match, even remotely closely, the extant sample. Of course the claimant then pronounced that it was impossible to measure colour accurately from a colour photograph, etc., without appearing to realise that such huff and puff undermined his own original claim. Subsequently information was received indicating that the same extant paint sample has exhibited considerable ambering or "browning" over recent years, attested to by museum staff and other interested observers. The colour claimed was Munsell 7.5 Y 5/2 and the two plates above show the actual results of the photographic analysis of the "corroborating" colour, the closest Munsell and FS equivalent values.

We are going to get technical about paint degradation and colour shift in the second part of this article, to illustrate exactly why and how it happens. To hold up a 65 year old paint sample and ignore degradation and colour shift is to omit a significant research factor in understanding the original colour.

This article is the output from factual and original research into the subject of paint ageing and deterioration made in consultation with qualified and recognised experts in this field. It should be read in the context of previous postings in the Olive Grey series.

Image credits: 2-6 (J3) sample via James F Lansdale; Rendered colour chips © Straggler 2009

Tuesday, 4 August 2009

Special Hobby's 1/72nd Nakajima Ki-43-II Hayabusa

Courtesy of the kindness and generosity of Ken Glass I have been able to examine the new Special Hobby 'Oscar' kit in 1/72nd scale. This is very much an "in-box" review as I have not had the opportunity even to test fit the parts.

The kit comes in a robust, and huge for the model (12" x 8" x 2"), top opening box in Special Hobby's attractive new design. It is marketed as a "Limited Edition" Ki-43-II Ko but actually represents what Aero Detail 29 identifies as a 'Model II Mid-Production' type and James I Long records as a Ki-43-IIa or 'Ko' Late type. The designators 'Ko', 'Otsu', 'Hei', etc., (approximately equating to 'a', 'b', 'c' in meaning and intention) were more usually associated with armament changes and their usage for the Hayabusa II series lineage is not universally agreed.

On opening the box one is immediately struck by the similarity of the parts breakdown to the Hasegawa kit from 1982. There are four sprue frames, three in mid-grey plastic and one transparent. The main frame which fits the box contains wings, tailplanes and most of the detail parts, two smaller frames contain the two fuselage halves and the engine cowling, oil cooler parts and exhausts respectively and finally a transparent frame contains the canopy parts and leading edge landing light transparency. The surface detail is light and delicately engraved. Although the fabric flying surfaces reveal the underlying metal framework in "shrink-wrap" style rather than a true representation of doped fabric tautened over the frame with rib tapes added it is not as exaggerated as on some other kits and should look fine under paint. The plastic seems less "rubbery" and vinyl-like than on some MPM/Special Hobby kits, which is welcome, but it remains to be seen how it behaves with glue. There is a moderate amount of 'flash' on some of the parts and, probably due to moulding considerations, some of it is in unwelcome places. For example on the delicate undercarriage legs the flash is on the more visible forward and rear faces and may be difficult to remove from the concertina oleo boot.

There are absolutely no resin or photo-etch parts in this kit. It is all plastic which for this reviewer is fine but others may be disappointed especially when considering the price. The instruction sheet advises that a separate photo-etch sheet of detail parts is available from MPM as catalogue # K72001 - and from the small illustration this seems to be pre-painted. It does not appear to be listed there yet though.

Interior detail consists of representative framing on the fuselage halves (an improvement on the Hasegawa kit) and a nine part interior - floor, seat back and pan, control stick, rudder pedals, instrument panel with engraved detail, sidewall fuel gauge panel, oxygen bottle and gunsight. Perfectly adequate for the scale especially given the size of the cockpit aperture.

The cowling is in three parts with two separate side panels that appear to capture well the slightly bulbous appearance of the original in plan. The engine is a half-moulding, like the Hasegawa kit, and the detail looks a little heavy handed and crude on this. The oil cooler is in three parts and superior in shape and form to the Hasegawa kit. The inclusion of the earlier, smaller oil cooler suggests there may be further kits to come and it will be interesting to see if Special Hobby eventually release the first true kit of the Ki-43-II early production aircraft. The exhaust pipes are the early, non-thrust type but are much better than those in the Hasegawa kit which depicted the outlets as round "tubes".

The kit contains both early and late style drop tanks, together with racks and shackles, but there are no locating holes or marks in the wings for these - they have to be "measured in". The kit instructions refer to fixing the later style tanks in the positions outboard of the undercarriage which are only applicable to the II series late production types. The wing leading edge landing light is also only applicable to late type Hayabusa II so Special Hobby seem to have become a little confused over their variants. These are relatively simple fixes, especially as the early drop tanks are included, but the absence of thrust type exhausts limits the flexibility of the kit. Hasegawa to the rescue as the thrust exhausts are optional in that kit - rather ironic. Both types of cockpit headrests are included with the larger type marked "not for use".

The upper wing includes interesting cutouts for the mechanism of the "butterfly" combat flaps which are molded to the single-piece lower wing, but the flaps are not depicted as separate components and are not much of an improvement over the poorly represented Hasegawa flaps.

The canopy is in two parts so that it may be presented open - a nice touch.

The airscrew unit is a surprising throwback to the technology of earlier kits and consists of a spinner with recesses that fits over the propeller - there is no back plate.

The undercarriage fairings are reasonable, with framework detail on the inner face but SH have replicated Hasegawa's crude design in depicting the upper fairings as heavy right angled "flanges" rather than the thin hinged extensions that they were in reality.

Unfortunately the "not for use" parts do not include a fuel cooler.

Colour and Markings

The kit provides for four markings options but surprisingly the painting instructions are not in colour:-

1. A Ki-43-II Ko of the 33rd Sentai's 2nd Chutai in New Guinea, "white 5", which is usefully the subject of a colour photograph. SH suggest dense green mottle over natural metal but the base finish could be light grey.

2. A Ki-43-II Ko of the 47th Sentai's 1st Chutai in Japan, "white 36", with Homeland Defence bands.

3. A Ki-43-II Ko said to be of the 63rd Sentai's 3rd Chutai in New Guinea, "yellow 02". This tail marking has never been satisfactorily explained and has been depicted in various ways over the years. In the original photograph the rudder fabric is missing so the actual design cannot be discerned. Personally I have my doubts that this is a 63rd Sentai aircraft and think that it may be from the 33rd Sentai - but even then the visible part of the tail marking is not quite right for that unit either.

4. Ki-43-II Ko of the 77th Sentai's 1st Chutai in New Guinea.

The small decal sheet, with wing Hinomaru for one example but two designs of fuselage Hinomaru, one with white outline and one without, is printed by 'DEAD Design'. Colour and saturation look good and a very nice touch is the provision of stencilling which includes full markings for the droptanks too.

SH suggest that the drop tanks on all these options are painted yellow but go here for other possibilities.


What you get is a mid-production II Series Hayabusa which SH suggest you put late production droptanks and a landing light on. The parts for early droptanks and a late production cockpit headrest are included - but not for the thrust type exhausts. It is possible late type drop tanks and landing lights were retro-fitted to earlier machines - I haven't made a study of that from photographs. Provided care is taken over these details and the actual configuration of the machine to be modelled is checked these anomalies should present no problem. In the interim the thrust type exhausts may be taken from the earlier Hasegawa kit to build a late production II. Whilst the kit does contain the early style oil cooler there is no annular cooler for the engine and the wings are the reduced span type so an early production II cannot be built from it out of the box.

Overall shape and dimensions appear OK - although I have not checked them in detail against plans - which plans?! The kit does not appear to incorporate the strange "broken-back" effect which marred the Hasegawa 1/48th and Fujimi 1/72nd models although the line from cowling to cockpit and cockpit to tail does change angle slightly.

This kit, notwithstanding a build test, appears to be a definite improvement over the 27 years old Hasegawa version, especially for those who prefer engraved rather than raised detail. But I venture it is not a quantum improvement and comes at a relatively high price.

I will post images of the sprue frames and decals later.

Image credit: Box Design © Special Hobby 2009