Friday, 31 December 2010

Happy New Year ~ あけましておめでとうございます

Very best wishes for the New Year 2011 to all Aviation of Japan readers.

Image credit: 'Snow at Miyajima' woodblock print by Hasui, Kawase (1883-1957)

Wednesday, 29 December 2010

Japanese Biplane Models in 1/48th scale

Further to the display of his superb Ki-3 model at Telford, Peter Starkings has kindly shared these images of more wonderful models from his 1/48th Japanese biplane collection.

Ki-3 from Choroszy Modelblud resin kit


KDA-5 from Raccoon resin kit

Nakajima "Bulldog" Lindberg kit conversion

Ki-4 from Planet Models resin kit


Image credits: All photos ©2010 Peter Starkings

Tuesday, 28 December 2010

A Model's Kawasaki Ki-32 "Mary"

It is a great pleasure to present here images of Jose Luis Fauste's splendid Kawasaki Ki-32 "Mary" (Army Type 98 Single-engine Light Bomber - Kyuhachi-shiki keibakugekiki) in 1/72nd scale built from the A Model kit.  Jose kindly provided comments about this build as follows:-

"I assembled this model two and a half years ago and I still remember the battle with this kit!

"The quality is typical of A-model short run kits with a lot of work necessary to finish the model properly. All the pieces are very thick with undefined edges in several areas, so carefully sanding and shaping all the edges is important. The interior of the cockpit is almost empty and the addition of several parts is needed. The canopy transparency is very thick and I recommend applying Future to improve it. The rear gun was useless, so I used one from another kit. The small windows in the fuselage sides were made using Micro’s Cristal Clear, as the parts from the kit are very poor; the fuselage locations for these windows must be opened up to the proper size (more or less….).

"The general fit of the model is poor mainly in the wing to the fuselage area with a lot of putty and sanding all around the joint; the worst area is the rear part of the upper wing and lower area. An unusual feature feature is the tires separated for the wheel. The panel lines are fine and fairly defined in several zones. The exhaust stacks also need a sanding of the surface to define the shape and the nose air intakes must be opened up.

Finally the decals are very thick and matt, with a lot of support paper around it. In the end I used decals from the scratch bag for a 45th Sentai airplane in China, perhaps in Hong Kong at the end of 1941?
The model is painted with Gunze IJA gray, IJA green, Mahogany and RAF middle stone as I don't have reliable information about the colors used on this aircraft in China; any new information about these colors is welcome."

A Model produced two variants of this kit which differ only in the colour schemes and decals offered. Prior to this release the charismatic Ki-32 had been tackled a few times in 1/72nd scale by short-run, vacform and resin manufacturers but it is surprising that there have been no mainstream injection kits of this type, together with its sister light bomber type the Mitsubishi Ki-30 "Ann". 

Merlin Models short-run, limited issue kit was produced in 1985. It is said that you have to be a magician to build Merlin's kits and by current standards they are crude indeed. Nevertheless, Merlin seem to have captured the "chunky" appearance of the real aircraft better than any other. Some of the more modern kits appear too long and slender in the fuselage dimensions. The Merlin kit has an injection molded canopy but it is a poor fit, being narrower than the fuselage and resulting in a lip unless drastic modifications are made. Mine, begun in 1985, is still not finished, mainly because of the canopy issue, but I like it enough to persevere to complete it "one day"! The plastic is robust and easy to work, reacting well to cement and facilitating a very strong construction. The exhausts are terrible and I pinched mine from an Airfix Me110, suitably modified. Time spent on the cowling panels of any Ki-32 kit is well worth it as the finished model derives much of its character from the engine.

The Aviation Usk kit dates from 1993 and may still be available as an Xotic-72 kit (?). It was nicely presented and quite cleanly molded, with a vacform canopy and decals for no less than four different machines, three camouflaged and one in overall grey-green.

The FE Resin kit was issued in 1998 and is a very cleanly molded resin kit with vacform canopy. A single set of markings is included. This kit was unusual in providing a full engine assembly.  The shape and dimensions of the fuselage are suspect, however, giving a slender, elongated appearance not typical of the real aircraft.

There is another resin kit available from Choroszy Modelbud and vacform kits were produced in 1979/80 by Eagles Talon and Wings-72. There was also a 1/48th scale resin kit from Try Angle of Japan.

Notes on Colour Schemes

The tri-colour so-called "China scheme" has featured in art and profiles of the Ki-32 for many years and has been represented in various ways. In addition to the most common variant, as depicted by the A Model box art with two shades of brown and a dark green, there are depictions showing brown with two greens, lighter and darker. There are also versions showing the blue dividing lines or "rivers" between the main camouflage segments and these are shown in both a darker and lighter blue. After settling on the combination of colours modellers are then faced with determining what the actual colours looked like and there are many possibilities to be drawn from kit instructions, profiles, art and models.

The basic tri-colour scheme imitated that used on Army tanks and armoured vehicles during the Sino-Japanese War and consisted of a khaki base colour (カーキ色) with camouflage segments referred to simply as green (緑色 midori iro) and brown (茶色 cha iro). Ichiro Hasegawa described the colours as "tan, dull brown and dark green" which seems fair enough. The khaki base colour imitated the colour of Japanese Army uniforms and was a surprisingly dark and yellowish "mustard" but could often show a slightly more greenish or light olive appearance. It faded very rapidly towards a washed out sandy colour. The green was a somewhat bright colour but had a tendency to degrade with UV exposure towards a more olive or brown appearance which some veterans described as "reddish green". The brown was a medium, slightly reddish brown but tended to fade with UV exposure to a lighter, more orange colour. The colours presented here may be viewed as "typical" and are rendered from measured values of the standard swatches together with adjusted versions to show the typical degradation where known. Surprisingly there are no usefully close equivalents to these colours in the Munsell, FS595B or RAL standards.

The approach taken towards camouflage during this period was flexible and the instructions often ambiguous. Specific colours and their prominence in the overall scheme were recommended for geographical areas such as the "Southern fronts" or to accommodate seasonal changes if there were time to do so. Inconsistency in the way the colours are described in the official instructions, recalled by personnel and/or designated in the official standards creates difficulties in attempting to be specific about them. The camouflage schemes were not factory applied and therefore differences in both colours and patterns as applied by different depots or units are to be expected. Broadly similar patterns as promulgated in official but crude sketch plans could also appear different in photographs as a result of individual applications, overpainting to change ownership or censorship to conceal unit markings.

The idea of two greens may have arisen from the use of another formally adopted Army scheme combining the khaki and green with indigo, a dark, slightly greenish blue. This scheme has been confirmed as being applied to the Ki-27 aircraft of the 24th Sentai and may also have been applied to Ki-32 aircraft of the 45th Sentai participating in the attack on Hong Kong.

The factory finish of the Ki-32 was the Army colour # 1 Hairyokushoku (ash green colour), the precise appearance of which is still argued about. This paint colour, lustrous when new, quickly oxidised and faded towards a dull, more neutral or blue-grey appearance. The 1927 standard archive sample is lighter and brighter than Tamiya's XF-14 JA Grey although both share the same hue. Another sample swatch shows a much stronger, sharper pale blue-green colour which reflects the appearance of the colour in some colour film and photographs. Later variations may have been more olive-grey in appearance, perhaps even approaching a dull mustard colour as described by some eyewitnesses. These multiple variations were probably due to the authorised range of variation in paint colour allowed for by the Japanese Army (which permitted an astonishing DE difference of between 4 and 5 in most cases), pigment procurement issues, manufacturing differences, batch differences and the inadequate mixing of the base ingredients, a common problem with paints of that era.  Advice here to modellers is to relish and explore these variations rather than to fret about them.

Red Tails of the 75th Sentai on "grey" Marys - an attractive option for a model. 
The leading edge "flash" was yellow - not as depicted here.

In Service

From a WWII perspective "Mary" is perhaps best known for its last operational use in the attack on Hong Kong by the 45th Sentai, an event which is the subject of famous film footage. This shows the type attacking shipping and harbour installations, then participating in a mass formation victory fly-past over Hong Kong's Victoria District. But even here a mystery persists, as many sources record the 45th transitioning to the Ki-48 Type 99 twin engined bomber well over a year before the attack. Eyewitnesses describe "Stukas" of Ki-32 type dive-bombing the airfield and ships in the harbour. The early Ki-48 was not capable of dive-bombing so perhaps the 45th retained a Chutai equipped with the Ki-32 essentially for this type of attack? On the other hand it is known that both the Ki-36 and Ki-51 spatted types participated in the attack, so was the well-known film just a propaganda effort intended to divert attention from the more modern Ki-48? Ichiro Hasegawa mentions the Ki-32 being used for dive-bombing with ordnance fitted to wing racks and the bomb bay unused. He further speculates that had the bomb bay been dispensed with for wing-mounted racks the Ki-32 would have had a slimmer profile but my feeling is that the designer probably exploited the engine and radiator depth requirements in configuring the bomb bay. See update!

Trouble with that "BMW" again!

The Ki-32's Kawasaki Ha-II liquid-cooled engine, known as "BMW" to the ground crew despite its indigenous manufacture, was notoriously unreliable. Ichiro Hasegawa observes that it was only the escalating Sino-Japanese conflict that persuaded production and records the underpowered aircraft struggling "hard for every take-off trailing a long after-burning flash that scared spectators". He also mentions "troubles such as cracked cranks or rods sticking out of case and engine cover".

Note dive angles marked below windscreen

Surface finish was reported to be very fine and smooth with "not trace of rivets" said to be typical of Kawasaki products. The distinctive engine panelling presents a contrast to the rest of the airframe. The paucity of plans and photographs makes determining the actual arrangement on top of the cowling ahead of the windscreen and the position of the single cowling located machine gun difficult.

The operation of the rear canopy was similar to the Ki-48. It consisted of three sections, a fixed forward section and two movable rear sections. The rearmost curved canopy pivoted upwards under the middle section which could then be slid back over the fixed forward section using two handles attached to the inner frame. The sliding section of the pilot's canopy slid back over the solid fairing between the two canopies.

Image credits: Model pics © 2010 Jose Luis Fauste ; Kit box art © manufacturers as mentioned; Rendered colour chips © 2010 Straggler; Photos and postcards author's collection

Saturday, 25 December 2010

The Colour of RLM 02 Grau (Grey)

This may seem somewhat OT for this blog but as part of an ongoing investigation into early Zero colours a series of photospectrometric measurements of samples of the German RLM 02 colour Grau (Grey), sometimes referred to as Grungrau (Green-grey), were recorded from various sources together with difference-calculated comparisons in  Munsell, FS595B and RAL Standards. The results are presented here in the accompanying schematics as a resource, showing the original colour in sRGB format calculated from the the measured L*a*b* values and their closest Munsell, FS595B and RAL equivalents. Difference calculations of DE2000  less than 2.0 = a close match but for completeness I have included those closest Munsell, FS and RAL values even where they exceed 2.0. Also for completeness a table showing the measured L*a*b* and sRGB values from which the chips have been rendered is included here. Two chips are included in the Monogram publication and measurements taken were slightly different so again they have both been included for completeness.

The measurements were taken from the relevant standard and reference source paint chips - not from examples of applied paint - so please bear in mind that distinction which is always emphasised here. When some people enthuse about the paint colour varying - and it did to the extent that the Luftwaffe told their personnel not to worry about it - they can often infer that paint colour standards are useless for modelling purposes. This is to misunderstand the purpose and value of the standards. Rather than pinpointing how each and every aircraft might have been painted they provide a benchmark for the intended average colour to be visualised, which in the absence of documented and accessible samples of extant paint, might otherwise be in a vacuum Even with extant samples of applied paint many authoritative researchers and authors still have to rely on colour photographs, subjective visual comparisons and/or descriptions in order to communicate the colours. Standards can be used to triangulate this information. Again, it may be worth emphasising that the purpose of this blog is not to promote an agenda but to explore and discuss subjects in order to provide a resource by which informed decisions might be made. It is not in competition with anyone and challenges to statements in other forums as being inconsistent with the evidence should not be misconstrued as such. Besides, it's your model, painting or restored aeroplane, not mine!

One extant formula for this paint as a "Rubber Varnish gray N 243" is included in Jerry Crandall's 'Focke-Wulf Fw 190 Dora' Volume 2. It is given as Titanium Oxide and Zinc whites with three yellow pigments Hansa Yellow, Zinc Yellow and Yellow 420 N and, apparently, what may be RLM 66 dark grey (?). If the designation does not mean the latter then the formula appears to be missing a black or grey pigment.

Another RLM 02 formula comes from Herbig Haarhaus A.G. of Koln in their trademark 'Flieglack' series of fire-resistant lacquers. This is for Aviation Lacquer 7115.02 in their Herbeloid series. No less than 73.03 parts of the formula made up a proprietary lacquer binder/solvent consisting of 'vinoflex', butanol, butylacetate, toluol, spirit and ethyl acetate to which the following pigments were added:-

Antimony white (Timonox RS) - 2.94 parts
Chrome green - 0.08 parts
Titanium dioxide (white) - 2.15 parts
Chrome yellow - 0.18 parts
Sechsbrandruss - 0.02 parts
Aluminium bronze - 0.59 parts
Essigather (ethyl acetate) - 16.44 parts
Black paste - 3.47 parts
Red paste - 1.10 parts

Interestingly, ethyl acetate appears twice in the formula, as 17.60 parts of the binder/solvent and in the proprietary 'Essigather' with the pigment as 16.44 parts. The lacquer was intended to be spray-applied with equal parts of thinner. 'Vinoflex' was a polyvinyl chloride made by I.G. Bitterfield. 'Sechsbrandruss' was a proprietary six times refined carbon black pigment. 'Timonox RS' was a proprietary fire-resistant form of lead white. Chrome green is correctly a green mixed from chrome yellow and Prussian blue but was also used, incorrectly, as a generic term for chromium oxide (green). Aluminium bronze was a leafing pigment usually added to improve impermeability to moisture and thereby resist corrosion and gave the paint its earlier description of 'silver-matt grey'. The formula is more complex than expected and the type of pigments used for the black and red pastes unknown.

Note the differing extent of yellow pigmentation in the two formulae which gave the colour its distinct appearance. RLM 02 hobby paints which present an entirely neutral grey or cool grey-green do not capture this slightly "warm" yellowish character. The schematic below shows the measured comparison of three hobby paints to the Kiroff RLM 02 sample. Two of the paints are lighter (as one might expect) but greyer from the introduction of a higher proportion of white pigments

As can be seen, a consistent Munsell equivalent value of 7.5 Y 5/1 has been calculated in this analysis, but although very close it still does not quite convey the true yellowish caste of the original colour. There are no usefully close FS595B comparisons; the closest, 34201, is too yellow. Two RAL values, 7002 Olive grey and 7003 Moss grey, offer useful comparisons, the former probably providing a slightly better average visual comparison than the latter which strays towards a cooler grey-green in character. But the comparisons probably highlight a variance present in the original paint, sometimes warmer sometimes cooler. RAL 7003 is available in hobby paint as Revell 45 'Light Olive' but has not been tested against the samples.

Please bear in mind that all the chips are probably slightly darker than they would have appeared 70 years ago. The type of yellow pigment in use probably ensured that thermally aged browning was minimal but the paint as applied probably appeared slightly lighter and almost certainly brighter.

Image credits: Rendered colour chips and table © Straggler 2010

Thursday, 23 December 2010

Hayate Film

I was studying the well-known Akeno Hayate film, pursuant to something else entirely (but not wearing my anorak), when I noticed something interesting for the first time. There is a "coating" along the whole length of the fuselage, broken only by the natural metal reflection just below the cockpit and at the wing root. At first I thought that this was just non-reflection of the metal surface - but it isn't. It appears to sit over the sparse green mottle, which makes me think it is some form of residue from the engine (oil?) or staining from the exhaust, but I'm not sure. If it is the latter then it is not the type of staining usually associated with exhaust effluence as it appears to have spread a fine and constant film along the whole length of the fuselage. Perhaps the result of that "fan" of thrust exhaust pipes? If it is oil maybe that is what is so engaging the two groundcrew's attention?

Is it overspray from the mottle? Don't think so - too smooth and regular. A coating over the natural metal? Maybe. But as mentioned it appears to be over the green mottle not the other way around. This "coating" runs to the length of the tail and also appears to be the cause of the "greying" of the Hinomaru border but more curiously seems to be over the wings too, which show little or no reflection from the natural metal at all. The latter may be just be the result of a denser mottle applied to the wing upper surfaces as discussed before. Whatever it is it's probably worth a passing thought if and when reproducing a Hayate scheme like this.

Image credits: Akeno Ki-84 film stills author collection.