The Colours of RAF/AVG Tomahawks Part One

With the imminent release of the new Airfix kit the subject of Curtiss Tomahawk colours for RAF and AVG subjects will probably be chewed over yet again and already a thread at Britmodeller has touched on some of the issues. Previous references, particularly those cited as supporting the idea of light gray under surfaces, get bandied about rather uncritically, so I think it is worth re-emphasising some of the substance of what has actually been recorded.

I already quoted from Terrill Clements 'American Volunteer Group Colours and Markings' (Osprey, 2001) back in January 2009 and felt the need to repeat that in the Britmodeller thread, but some of the other observations in his comprehensive and excellent study also bear mentioning here (my emphasis):-

"Curtiss employed DuPont enamel camouflage paints on its products in 1940-41, and this included the brown and green colours used on the pattern camouflage of the Tomahawks shipped to Burma. The Dark Earth brown colour (DuPont 71-065) appears to have been visually identical to Army Air Corps colour Rust Brown 34, while DuPont Dark Green (DuPont 71-013) was virtually identical to Army Air Corps Dark Green 30. Whether they were those specific colours is uncertain, but they are certainly indistinguishable from them, and also 'close enough' to the green and brown in use by the RAF."

"Curtiss employed other colours on its fighters. however, including a sandy earth brown colour (DuPont 71-009). This shade has no analogue in the pre-war American colour standards, but it is similar to British Light Earth, and was perhaps intended for use on Desert Air Force Tomahawks. Period colour photos suggest that this colour was used on a few of the AVG's Tomahawks instead of the darker brown. Second Squadron pilot Robert Layher recalls noticing that, when seen side by side, some AVG Tomahawks had more 'vivid' camouflage on top than others. But it is unlikely that many casual observers would have noticed any significant difference between the colours on Curtiss's products and those aircraft painted more exactly to British standards. Even fewer would have cared."

The first point to notice is the acceptance that DuPont paint colours were being used by Curtiss during the time period of Tomahawk production. There is no suggestion that other paints were used so the question immediately arises - why should the under surface paint have been an exception?  And yet we are sometimes asked to believe the suggestion that for some reason, perhaps poor quality control, Curtiss procured different paint, of a different colour, for the under surfaces of Tomahawks rather than using DuPont's equivalent(s) to MAP Sky.

The second point, and it is an interesting one, is the suggestion of some AVG aircraft having a slightly different appearance to others. Exploring the production and serial number history of the aircraft sent to China this seems perfectly feasible as they were drawn from distinct production batches. There are some issues about the way these deliveries have been described that will be explored in a future post.

DuPont's 1942 MAP colour card shows the 'darker' Dark Earth to be 71-035 rather than 71-065 but the latter might just be the result of a typo or misreading somewhere along the line (71-065 was actually Deep Sky Blue!). The allocation of the number 71-021 for DuPont's Sky Type S Grey suggests that this was not a later colour although there are no Curtiss documents that tie it conclusively to Tomahawk production. I doubt that the 'lighter' Dark Earth 71-009 was based on MAP Light Earth as DuPont offered this paint colour separately as 71-048 and in the early days of the Desert Scheme Light Earth was an authorised substitute for Middle Stone. It is more likely that the different Dark Earths relate to the camouflage contrasts intended to be achieved by the Temperate Land and Desert schemes. The Curtiss P-40E factory paint drawing (showing AK571) makes it clear that 71-035 was intended for the Desert Scheme whilst 71-009 was intended for the Temperate Land Scheme. This raises an interesting question about the AVG Tomahawks which will be addressed in due course.

In an article on Kittyhawk colours in the September 2002 IPMS Seattle Chapter newsletter Mr Clements wrote (again my emphasis):-

"The absence of a DuPont stock number for the “Sky Type S” is perhaps not accidental. Period color photographs reflect that in practice export Kittyhawks were finished with colors that tended toward either a pale blue or a pale gray. Some students of the subject still believe that a color that actually looked pretty close to RAF “Sky” (you know, that sickly yellow-green-gray color) was used as well, although photographic evidence of this is lacking. A similar range of blue and gray shades can be seen in color photos of export aircraft built by other manufacturers during this period. The Bell Corp. in fact identified “Sky Type S Grey” on a January 1941 Airacobra painting diagram as DuPont 71- 021, and the few color photos of P-400 Airacobras suggest to me that this was a color very much like RAF Sky Blue. It should be noted that DuPont also referred to 71-021 as Duck Egg Blue. Some color photos suggest that a light blue used by Curtiss also looked much like RAF Sky Blue, and that Curtiss’ light gray looked very much like RAF Sky Grey (or the very similar US Aircraft Gray). Considering the nature of such “sky” camouflage colors and the inherent limitations of photo interpretation, these colors perhaps merely represent extreme manufacturing variances of one specification. But it seems more likely that this was an attempt to respond to confusing directives. (If you can find them, read wartime British camouflage directives, and just try to figure out the bottom colors!) Or perhaps the gray paint was simply an expedient substitution for the blue due to shortages or a perceived need to somehow find a middle ground between US Army and RAF requirements. Or all of these!"

And he concluded that:- "Curtiss’ “light blue” was DuPont 71- 021 Duck Egg Blue, a color very similar to RAF Sky Blue."

Here are three actual samples of MAP Sky Blue as applied to RAF aircraft illustrating the slight variance to be found in the applied paints, together with a sample of DuPont 71-021 shown adjacent to a sample of MAP Sky. 

Despite the apparent differences I think Mr Clements' conclusion about the appearance of 71-021 is a reasonable one, especially as samples of paint from the undersurface of a Soviet Tomahawk recovered in Russia are also very similar in appearance to MAP Sky Blue. Although the colour card chip of 71-021 appears closer to MAP Sky and slightly more greenish the actual paint samples are cooler and more blueish, giving the impression of a paint colour almost midway between MAP Sky Blue and MAP Sky. However, DuPont also included Sky Blue as a separate colour in its MAP range of paints as 71-061 and it appears to be a stronger more saturated blue than the MAP colour. What was it used for?

I have an abiding belief, based on snippets of evidence relating to Grumman Martlet, Brewster Buffalo and Curtiss Mohawk colours that early US attempts to match to Sky - or more correctly "duck egg blue" - resulted in cooler, more blueish colours similar to MAP Sky Blue and DuPont Sky Blue. When we come to examine RAF Tomahawks the snag in this belief will become apparent! 

An issue with the comparison and matching of US Aircraft Grey (ANA 512) to MAP Sky Grey was addressed here in a post that also examined other greys proposed for Tomahawk under surfaces. In that post ANA 512 (based on a supposed match to FS 36473) appears slightly more greenish than Sky Grey which was a true neutral grey consisting only of black and white pigments. However I discovered that this slight grey-green appearance of Aircraft Grey (ANA 512), especially as it relates to FS 36473, might be fugitive. The pigments used in Aircraft Grey were Titanium dioxide ( a pure white at about FS 37875) and Carbon black (a dead black at about 37038), resulting in a neutral grey without any other colour tinting. The "neutrality" of a neutral grey can sometimes only be properly appreciated by comparing it directly to a "warm" grey (tinted yellow) or a "cool" grey (tinted blue or green) but there is a recognised tendency for all neutral greys to appear blueish under certain illuminants. The selection of Aircraft Grey as a possible colour value for Tomahawks seems to have been based on this idea that US manufacturers must have resorted to existing US colours as matches for the RAF colours and then looked for the closest colour to Sky Grey. With the established existence of 71-021 and its identified appearance I'm not sure that supposition was/is valid.

To be continued.