Airacobra Mk I

Bell Airacobra I, Special Hobby 1/32nd scale by Pat Camp

Part 1 – Some history and quick review of the kit.

(1) Nice kit box art – with an interesting brown border painted between the grey and green upper surfaces.


I can still recollect – even though it was over four decades ago! – the first time I saw a photo of an Airacobra: I fell in love with it. And I was not the first to have been seduced by its charms – it seems the British purchasing commission were so impressed by what they were told in those dark times of 1940 about the aircraft’s high speed, powerful armament and impressive rate of climb, that they ordered 675 of them sight unseen to complement the Spitfires and Hurricanes in the fighter battles against Germany. Unfortunately, tests of the first aircraft to arrive in Britain in July 1941 caused serious disappointment – they did not perform as they had been hyped to do, being inferior to both the Spitfire and Hurricane (and, more importantly, the Bf109!) It seems the difference in performance from that quoted by Bell may be accounted for in that the test aircraft was unarmed, lacked its 120 kg of armour plate, had a turbo-supercharged engine (the turbo charger being deleted from production aircraft) and polished flow surfaces. Yes, I can imagine those factors making a slight difference, particularly as the missing armament included a 37mm Oldsmobile T9 cannon plus ammunition, a pair of .50 cal and four .303 machine guns. In fact the test aircraft weighed around a tonne less than the production versions!

The aircraft was actually designed around its main armament and the 37mm cannon firing through the centre of the propeller hub was well supported and accurate. The displaced engine was located immediately behind the cockpit and was a liquid cooled Allison V12 delivering 1150 hp. The cooling system was highly vulnerable to damage when the aircraft was attacked from behind. It also seems that the 37mm was prone to jamming, as well as having a low rate of fire and limited ammunition. However, the RAF aircraft had the more reliable and faster rate of firing Hispano 20mm cannon fitted, although levels of carbon monoxide from the fired ammunition quickly built up to lethal levels in the cockpit.

601 (County of London) Squadron had the dubious honour of exchanging their Hurricanes for Airacobra 1’s in late September 1941. They experienced many problems with the aircraft and the Airacobra’s tricycle undercarriage was not suited to operating from grass airstrips. In terms of flying characteristics:

(2) Airacobra I UF-L of 601 Sqd, Aug 1941.


“Don’t give me a P-39, cos I value this life of mine

It will spin, it will roll, it will dig a deep hole,

So don’t give me a P-39″

You can (correctly) guess from this ditty sung by British aircrew that the P-39 enjoyed little popularity with the RAF. It saw very little enemy action. As a night fighter, the muzzle flashes were so intense the pilot lost his night vision and the exhausts were bright enough to be seen from 3 miles behind. It had great potential as a ground attack fighter, and its only enemy action with the RAF was in this usage, although the compass would be thrown out by up to 165 degrees when the nose guns were fired. The aircraft were withdrawn from RAF operational service as a consequence and shipped off to Russia, along with the remainder of the initial order for 170 aircraft that weren’t even unpacked from their shipping crates. After Pearl Harbour, some 200 Airacobras were diverted from Britain for service with the USAAC where, owing to the minor differences to their P-39D’s, were called P-400 and retained their original British serial numbers and Dark Earth and Dark Green over Sky camouflage.

I have to wonder, why didn’t they put the turbo back to improve the performance of the aircraft? And what would have happened if a Merlin was fitted in place of the Allison? Or a Napier Sabre driving a four bladed prop! – okay, I’d better take some sedatives before I carry on!

Not everything about the Airacobra is negative, though. I mean, at least it looks nice, doesn’t it ! But seriously, the Russians were able to put the Airacobras to good use in the ground attack rôle and it was a valuable asset to the Americans in their great time of need (even if it was no more popular with the American pilots than it was with those of the RAF).

The Special Hobby kit.

( 3 ) The Special Hobby kit

I was at a weekend model show in Montbrison (in the Auvergne) last Spring when I was overcome by an irresistible urge to buy a 1/32nd Spitfire. Thankfully (as it would later turn out), I was persuaded by fellow club member Alain Boissy to buy the Special Hobby Airacobra I instead (3). The reason being that it was a limited run RAF version and included resin and photoetched details – one fret being coloured. It was also, to my mind, really good value for money – a thought that has stayed with me throughout as I enjoy building this kit. This kit is – so I’m told – a great improvement over the first Airacobra offerings from Special Hobby. Indeed, I get the feeling that this kit has been produced by some real enthusiasts as it uses photoetch to replace moulded-on details and has different instrument panels, harnesses and propellers depending on whether choose to construct an RAF or RAAF machine.

So what is in the box? There are 7 sprues of light grey and one of transparent plastic parts. The plastic parts are of excellent quality: shiny smooth with finely engraved panel lines. The transparencies are excellent and came up well with a polish and dip in Klear. All control surfaces, apart from the flaps, are separate. Eduard do a nice PE set for the flaps, but as the RAF don’t normally park their aircraft with the flaps down then I have no intention of fitting these. Eduard do sets for the cockpit and wheel bays as well, but I don’t think there is a great need for these and I enjoyed making my own details anyway. In resin there are a choice of 12 or 6 port exhausts and a gunsight. The coloured PE set has two sets of instruments and seat belts, depending on the version you intend to build. The unpainted fret has engine covers, door and bomb details. The decal sheet looks very nicely printed and includes a full set of stencils, the positioning of which are shown on a coloured leaflet that also shows the three options that can be built from the kit: UF -O, AH585 and UF – , AH601 of 601 squadron (owing to the serial of the latter, it was thought apt to make this the commander’s (Squadron Leader E J “Jumbo” Gracie) aircraft, but records show he flew UF-M, AH577, more often). AH601 had the winged sword motif of 601 squadron in place of the unit code letter at the front of the aircraft. The third of the options is FA-F, A53-6, of 82 squadron RAAF based in New South Wales. All three sport similar camouflage schemes, although the tones are slightly different for the RAAF option. Interestingly on the RAF schemes, a dark earth line is shown between the grey and green camouflage. I spent quite a bit of time trying to figure this out.

Starting the kit build.

The cockpit and nose wheel-well were built up as a sub-assembly. Some detailing was done on parts before they were glued in place and other parts were left off to make access easier for painting.

A trawl of the internet will turn up lots of interior photos of the Airacobra. Many photos are of aircraft that have been restored or are in the process of restoration. I find those photos of unrestored aircraft to be more useful because you get a better feel for actual colours and for wear and tear. It also appears that the paint finish is not very well documented by Bell and so I enjoyed some time speculating about this. As mentioned in Part 1, the British Purchasing Commission seemed a bit lax about checking out the performance of the aircraft before ordering 675 of them sight unseen. However, there is evidence that, whatever they got, it had to be painted in the right colours. Colour chips of camouflage colours provided by the BPC were sent to Dupont by Bell. Considering it was quite a large order for Bell and the RAF were receiving early consignments, I reckoned they would use a paint mix matched to RAF Interior Grey-Green and this would be used throughout the interior. Incidentally, this is contrary to photographs of later airframes where it seems a variety of greens were used (probably parts supplied from different sub-contractors had differing tints of paint) with small fittings painted in silver.

Cockpit Seat.

There are some nice photos of a P-39Q airframe undergoing the early stages of restoration and this shows the seat to be red-brown phenolic composite riveted to a metal frame. Distinct variations in tone can be seen in the strips of resin impregnated cloth that were laid at angles to each other for strength and stiffness. However, whether this seat is unpainted / stripped of paint or had the paint otherwise fall off over the course of years is hard to tell. As is typical in our hobby though, I also came across a contemporary photo of AH601 that suggests the seat was not only made of metal, but was of a very dark colour! In weighing up the conflicting information, I decided to paint the seat in the red-brown as it would add a nice splash of colour and give me the chance to practice for the Spitfire seat that I hope to do in the near future!

(4) Fettled seat with plasticard strip added to represent stiffener on phenolic resin seat. Also visible is photo etch part that needed filing and bending to get a close fit.

The kit seat is generally of the right shape, but a little on the thick side. I spent a little time thinning the edges and giving the seat back more of an outward curve as indicted by the photos (4). A small cutout was made in the seat back for the seat harness in shown in the kit instructions, although I could not substantiate this from photos or logic as to what use it served! For painting, the seat was undercoated with a mix of white 34 and red leather 180. This was finished with a mixture of oil paints: cadmium orange + cobalt blue + Rembrandt Flesh ochre, with burnt sienna, burnt umber and cerulean blue also used for darker shades, using the internet photos for guidance (5). A couple of small mounting plates were painted interior green.

(5) Seat painting completed (well, almost!)

(6) Photoetch added and seat in place in the cockpit.

The kit includes pre-painted photoetch seat belts and these were bent to shape and temporarily held in place with Micro Liquitape until all the parts were correctly positioned before following up with superglue to secure in place (6).

Instrument Panel.

(7) Adding gauge bodies to rear of instrument panels.

(8) Instrument panel in place and wired up.

The kit has the choice of two designs of instrument panel depending on whether you are building an RAF Airacobra I or RAAF P-39F.

The panel has upper and lower sections and attaches to a plastic pedestal. This goes together neatly, but one of the things I missed (and it was not mentioned in the instructions) is that the upper part of the panel protrudes further forwards (by which I mean it comes closer to the pilot) than the lower section. A bit of PE bending was all that would be needed. The rear of the upper panel has instrument bodies moulded into the plastic part that is glued to the back of the PE. I added some further ones to the lower panel (7), plus wired everything up (8), although you can’t see too much once all is in place in the fuselage.

(9) Highlighting on instrument panel and gauge bezels.

Everything was painted dark grey, with shaded areas in black and highlights picked out in white – this included painting little crescent shapes on the instrument bezels where light would reflect (9). This required steady use of a fine paint brush – a bit demanding for my aging eyesight!

I tried a mixture of Faller “Wasser-Effeckt” and Johnsons Klear to get a thick transparent lens on the gauges, but I can’t claim this was any better than using neat Klear or Clearcoat.

There is also photoetch for the pedestal, and the instructions have you file away the moulded on detail before gluing the PE in place. However, I think it is worth keeping in place as it matches up with the gauges on the PE.

Cockpit Floor & Rear.

(10) Scratch details added to cockpit floor. Front nearside: semi circular humps (filed sprue), engine inertia starter switch (plastic rod and soda can), selector lever (kit PE) for automatic or manual raise/lower of undercarriage with handle (brass rod with wasser effect for shape) for pump unit, cooling damper shutter adjustment (kit PE on plasticard base), oil damper shutter levers (kit PE). Far side: throttle and mixture rods (plasticard and brass wire), release lever (brass with wasser effect knob) and fuel selector (spares box PE with plastic additions). Rear bulkhead: seat supports raised higher with plastic tubing, horizontal cross bar (plastic rod).

I glued the rear bulkhead to the cockpit floor and used the fuselage halves as a jig to make sure it set at the correct angle. The instrument panel pedestal (without the panels themselves) was also glued in place after I had drilled out holes in each end plus some small holes in the floor beneath it that would be later used to insert instrument lines. A side console was glued in place after a shrink dip had been filled and cleaned up and the moulded-on details filed off to be replaced by PE after painting.

Some photoetched parts are included in the kit to add some “bling” to the cockpit area, but I also enjoyed adding some scratch made details using photographs as a guide (10). It was also interesting to view one or two old training films on U-Tube to see further details and an explanation about what the various bits and bobs do and how you use them to fly the ‘plane – something which gives us an interesting additional insight into our modelling subject and those brave pilots who flew them in action.

Fuselage sides.

Whilst a throttle quadrant is provided in the kit, surprisingly there are no throttle, mixture or propeller pitch levers. I used PE fret for the levers, topped off with small knobs rolled from Duro epoxy putty.

(12) Additions to starboard fuselage side are oxygen regulator (sprue), fittings (plastic and soft iron wire) and piping (copper wire).

(11) Additions to port fuselage half include throttle levers, push rods for throttle and mixture, cable for propeller pitch setting plus small switches and knobs to the top of the electrical fuse box.

I made a lot of these so I could select sizes and have some left for later projects. Assembly is relatively easy with Micro Liquitape followed up with cyanoacrylate adhesive. A small switch with wire was added to the quadrant and push rods to match up with the cranks on the floor (11). Additions to starboard side are shown in (12).

Doors.

(13) Transparent door mouldings polished, dipped in Klear and masked ready for undercoating.

(14)Doors and inside of PE parts undercoated in dark green.

These are moulded in transparent plastic with photoetch panels and details. The main panels have curious slots relief etched on the reverse face and it was only after these were securely glued in place (15) did I realise what they were for: stiffening ribs. The idea (not that any of this is mentioned in the instructions) is to run a round ended tool along the smooth face and press the metal in to form an indented rib. Too late a realisation for me, so I cursed my dumb headedness. Also, after careful study of photos, decided that the very nicely etched map case on the right door was not fitted to the RAF aircraft, so I left it off and unpainted. I then watched a video on U-Tube and well, you can guess what I saw. So I folded and painted up the document case, but couldn’t get the colour to match!

(15) Doors assembled ready for painting in interior grey-green.

Anyway, I am getting ahead of myself a bit, because before the door panels could be glued in place the inside faces of the doors and panels were undercoated in dark green (14) to make sure that no unpainted metal would be visible after the model was painted. And before masking (13) and painting, the transparent glazing was prepared as follows.

Kit transparencies.

The kit parts are very good. The cockpit is clear, shiny and thin. Nevertheless, there were one or two slight marks / pips so I went over with 6000 and 8000 Micromesh used wet, followed by polishing and dipping in Johnsons Klear.

Painting the grey-green interior.

(16) Cockpit painted and ready or details to be added.

(17) Another view of the cockpit

The interior surfaces were airbrushed with interior green 78 lightened with white 34 with a spot of mauve 107 added to reduce the intensity of the green. Shadows were painted in with dark green oil paint mixed from chrome oxide green, violet blue and red violet. Highlights were oils mixed to the colour of “Sky” and applied to edges that would catch the light. Some details, such as the support for the undercarriage hand pump, used paint to simulate the cut-outs present on the actual part (16, 17).

Joy Stick.

(18) Kit supplied control column.

(19) Foundations of replacement – brass rod, plasticard and sprue.

(20) Epoxy putty mixture of Magic Sculp with Duro. Essence F used to help with smoothing the putty on the part.

(21) Completed and painted replacement in position.

The kit one was too short and thick. The moulds did not line up well either, so it would have been difficult to clean up well (18), so I replaced it with one made from scratch (19-21).

Nose wheel well.

(22) Details added to wheel well from copper wire, PE fret and plastic card and square section.

The underside of the cockpit floor forms part of the roof of the wheel well. To this, you add two side walls, a roof and a front and back. There is also a nicely detailed frame that the undercarriage links back to. It all seemed a bit reluctant to line up properly and some trimming was needed along with gluing in stages with gently pressure applied by hands or clamps the coax the parts to where they needed to be.

Much like the cockpit, I enjoyed adding some detail to “busy up” the affair, working with the individual plastic pieces before they were glued together (22).

Main wheel wells.

(23) Copper wire, wire insulation (to represent hydraulic fittings), plasticard and plastic rod used to detail the main wheel wells.

(24) Some careful shading and highlighting was used to represent the various cut-outs and panel work around the main well walls

The roof for the well is moulded into the lower wing and has good detail, but the side walls are smooth and a gross simplification over the real thing. I toyed with modifying it, but decided it could easily get out of hand, so decided to add selective detail only (23).

Painting the wheel wells.

(25) Work in progress on the nose wheel well.

This was done at the same time of the cockpit. Photo (24) shows paint being used in an effort to add detail and interest. Photo (25)  shows one of the nose well being worked on with a side wall left off so as to make access easier for painting.

(26). Nose wheel bay assembled and weathered using local pigments

The various plastic and PE parts were finally brought together, the paintwork touched in and then given some dirt and grime treatment using natural ochre pigments from the coloured terrain of Roussillon (about an hour away from where I live), using linseed oil used as a medium (26). I also applied this to complete the cockpit (27) ready for final assembly of the kit.

(27). Completed cockpit assembled to the port side of the fuselage.

Kit assembly and painting.

Assembling the fuselage.

The fuselage halves had some distortion and assembly had to be done in stages.

The cockpit and nose wheel bay were dry fitted between the fuselage halves and lined up carefully before gluing to one of the sides. Glue was applied from the inside by going up through the wing opening. The front end of the nose wheel well could be glued through a hole in the upper nose that a part with the machine gun troughs fits into.  A guide vane for the air intake behind the cockpit was also fitted at this time. This area of the kit was not so good and a lot of filing and filling was needed to give it the right look. A radio is supplied in the kit for fitting into the rear compartment, but this arrangement was not used on RAF machines and the radio was omitted from my model.

(28) Bottom right: lead and tungsten carbide drills used for nose weight. Note the aperture in the top of the nose. This is for a separate piece that has the machine gun troughs. This piece was left off until late in the build as it was handy for posting in more nose weight when it was found to be needed later.

The model will need plenty of weight adding to the nose and there is space available for this. My first estimate of ¼ oz of lead and a couple of broken tungsten drill bits was later increased by a further ½ oz and two more drill bits later on when the rather heavy tail assembly was added. Fortunately, the section in the nose for the machine gun troughs is a separate part and allows you to “post in” some more weight if you need to, and I decided to leave this part off until the main assembly of wings and tail was completed (28). The epoxy resin used for gluing the weights in place was also used to strengthen the join between the nose wheel bay and fuselage side.

(29) Bottom left: plasticard glued to rear underside of one fuselage side for alignment and support, not only for the other fuselage side, but for the wing as well.

I added a strip of polystyrene to the lower rear join (29) to help the edges line up and also give some support the rear end of the wing. (30) shows internal parts in place before gluing of fuselage halves.

(30) Top: internal parts in place before joining the fuselage halves together.

Gluing of the halves was done in stages, teasing the parts into place and constantly checking the alignment of mating surfaces, the cockpit and wing openings being at the same level on each side, straightness and absence of twist in the fuselage. Once this was all done, the cockpit and nose wheel bay were glued to the other fuselage side.

Assembling the wings.

The wing has a single lower piece and upper halves. Ailerons are separate.

(31) Some plasticard shim had to be placed on the port wing leading edge to get the wings level.

The trailing edges are very thick and so I thinned them down using 100 grit abrasive – even with this coarse paper it took quite a long time to do. A finer paper was used to clean up the surfaces once the edges had been thinned down to a sharp edge.

I did not thin down the ailerons. This was a mistake as they did not fit into the wing very tidily.

(32) The level of the wings was set by placing a steel straight edge across the cockpit opening and adjusting the packing shim until there was the same distance at each wing tip.

The lower wing was dry fitted to the fuselage. There were problems lining up the rear end and a lot of filing and trial fitting was needed. (34) shows the result and the gaps in the cooler outlet ducting can also be seen. All of the gaps were later filled with epoxy putty.

The cooling air intakes were fitted to the leading edges and then the air ducts were glued into place (33). Plasticard was used to blank these off at the far end and all the visible internal surfaces were painted dark green.

The lower wing was glued to the fuselage and checked for level by placing a straight edge across the cockpit and making sure the clearance at each wing tip were the same. Some plasticard packing was needed at the front end to get this right (31, 32).

(33) left and (34) centre: some pretty awful gaps and misalignments at the wing joins and various inlet and outlet ducts needed treatment with epoxy putty.

(35) Blue oil paint being used as “Engineer’s Blue” to get the best fit of the top wing to the fuselage.

The top halves of the wings were next to be glued into place. Some trial fitting was needed and the join to the fuselage was carefully filed to obtain a good fit. (35) shows where I brushed blue oil paint onto the fuselage side of the join. I then carefully lined up the top wing half against the join and where the blue paint touched showed up the high points. These were filed back until the blue transferred across the length of the join.

(36) The RAF machines look to have a different fin fillet to the one moulded in the kit, so I made some alterations using a mixture of Duro and Magic-Sculp putties.

The oil paint was then wiped off before gluing the wing into place. After assembly, Mr Surfacer was used to fill small gaps and misalignments. For major areas needing correction, I used a mixture of Model Sculpt and Duro, these were the air scoop behind the canopy, gaps in the underside of the tail to fuselage join, the front and rear underside joints of the wing to the fuselage. Additionally, the RAF machines seemed to have a different shaped fin fillet to that in the kit and this mixture of epoxy putties was used to correct for that as well (36).

The holes for the machine guns in the leading edge of the wing were of the wrong shape, so I drilled them out and inserted some plastic tubing of the correct bore.

The troughs for the machine gun blast tubes in the piece that glues to the fuselage nose was also modified. The aft end of the troughs was cut out on the underside and the covering panel thinned down to a realistic thickness. Semi-circular pieces of plastic tube were added to represent the blast tubes that run back into the gun compartment. The kit includes photoetched “eyelids” that are to be curved and fitted over the trough aperture, however, I could not see these in photos of the RAF machines and so these were left out of my build. Incidentally, it looks in one of the photos of RAF machines as if the guns troughs were left in natural metal finish – however mine were camouflaged.

(37) The kit allows the control surfaces to be positioned. I kicked the rudder over to the right and had the elevators drooped. The ailerons were left close to neutral.

The centre section of the wing has a pylon moulded in place. I could see not evidence of this either in the photos of RAF machines, so I filed this back as far as its mounting flange because bombs were installed later in the Airacobra’s career with the RAF and there was probably some mounting feature provided for this.

I searched through numerous photos to help me decide on the positioning of the control surfaces. The ailerons tend to be around the neutral position, whilst the elevators droop down by 10 to 15 degrees. The rudder can probably be any position: photos show straight or, as I decided for my model, some 20 degrees to starboard (37).

Before gluing the canopy into place, the gunsight was fitted. This attaches to a crossbar and has a separate transparent plate. The plate was edged with green oil paint to give a glass-like appearance. The metallic parts were painted Revell anthracite grey and shaded and highlighted with oils. A leather cushion was undercoated Humbrol 62 and shaded with brown oil paints.

The canopy had previously been trimmed for fit prior to polishing and being given the Klear treatment. It was superglued into place, unfortunately dislodging the gunsight in the process of attachment. No problem, the gunsight on its crossmember was re-installed again after painting of the airframe had been completed.

Preparing for painting.

(38) Preparing for painting – canopy masked with Tamiya tape. Cockpit packed with tissue and doors held in place with Micro Liquitape. Some other masking was done with Silly Putty but this was affected by the paint and lifted the paint when the masking was removed later.

(39) Here we can see the door lays proud of the fuselage. This was to cause problems with spraying and subsequent “micromeshing”. I think it would have been better to have painted the doors separately. Also visible in this view are the photoetched exhaust covers. These were attached temporarily, but – as it turned out - could have been fixed in place permanently at this stage.

The void space of the cockpit was filled with moistened tissue paper and then the doors temporarily positioned using Micro Liquitape to hold them in place (39). Unfortunately, the interior photoetch on the doors and some other details within the cockpit stopped the doors fitting flush to the fuselage. This was actually to cause me problems with paint finish and paint peeling later on, so I would do it differently next time.

(40) The wheel wells were masked with Tamiya tape around the edges and the centre filled with moistened tissue paper. Some diluted white glue was painted onto the surface of the tisssue whilst it was still wet to stiffen it up. Any remaining gaps were filled with Silly Putty. Also visible in this view are the various joints filled with epoxy putty and smoothed. The wing roots were given a coat of Mr Surfacer after having masked off the fuselage area. This masking was removed before the Mr Surfacer had set to leave a raised panel.

A better method would have been to run masking tape around the cockpit door surround and pack the interior with tissue paper, with a coat of white glue on the surface of the tissue paper to firm it up and hold it in place. This was the method used for the wheel bays and it worked fine (40). The method would have required the doors to be painted separately, but I think this would have been the best approach overall.

The transparencies were masked in-situ with Tamiya tape. With complex curved surfaces a prefer to use multiple pieces of tape in a way that reduces the amount of tape stretching – I have found in the past that this leads to residues of tape adhesive being left behind when the tape is later removed.

The tape is placed lightly onto the transparency and gently pressed into place. I then run a cocktail stick with the point filed to the shape of a screwdriver blade around the canopy frame to press the tape into place before trimming excess tape away with a new knife blade. I then cover the multiple pieces of tape with liquid mask to eliminate the chance of paint bleed through at the edges (38). I also check to make sure all the masking is properly stuck down before applying paint.

Kit painting.

I have said previously that I intended this to be a quick build: it has not turned out that way, one reason being the complexity of the paint scheme I had selected.

(41) Photo of 601 Sqn Airacobra taken August 1941 showing the curious dark border to the camouflage.

Bell supplied the Airacobras to Britain in a Dark Earth and Dark Green over Sky camouflage scheme as specified by the British Purchasing Commission (42). The paints were supplied by the Dupont Company under the brand name of “Camouflageline” and were produced to British D.T.D specifications.

(42) Here are a couple of photographs showing the paint scheme applied to the Airacobra when first delivered to England. Notice the high undersurface demarcation lines and also the tints of colours which are described in the text.

On arrival in the UK the aircraft were repainted in the newly issued camouflage scheme for day fighters of Ocean Grey and Dark Green over Medium Sea Grey. For the Airacobras, this was carried out by the RAF Maintenance Units and a “mixed grey” (7 parts Medium Sea Grey and 1 part Night) was used owing to Ocean Grey being in short supply. This is the finish they were in at the time of a Press visit to 601 squadron at Duxford in August 1941. By September 1941, supplies of Ocean Grey were available and the aircraft were painted in this finish and yellow wing leading edges were added.

There are numerous photos of the Press visit available in reference books and the internet and so I chose to base my model on these. Photographs of 601 Squadron Airacobras taken at this time show a curious dark edging between the upper camouflage colours (41). Special Hobby, in their painting guide and box art, have interpreted the dark band to be (Camouflageline) Dark Earth. However, (42) shows the Sky undersurface runs much higher up the fuselage than on the repainted aircraft and the dark edging is visible in these areas as well – which it could not be if it were Dark Earth – so I think Special Hobby are wrong on this point.

I also found that this topic had been debated on internet modelling sites as well. Mention was made that, to reduce overspray, the outline is painted in first by using a narrow spray nozzle and then filling in is done using a nozzle with a broader spray pattern. This can result in a darker band of the colour at the borders. I think this is the answer and, after studying the photos, I concluded the dark coloured borders were of RAF Dark Green. It seems odd, though, that the Operational Maintenance Units painted over the Camouflageline Dark Green (said to look more like USAAF Medium Green, but not so different as to be worth worrying about in my view), particularly when a new paint job would be carried out later once stocks of Ocean Grey arrived. I guess this was done just to confuse us modellers in the next century!

Colouring In.

This can be divided into three stages: pre-highlight/shade, camouflage and finishing.

Pre-highlight / shade.

(43) Start of painting: the model has been given a coat of primer apart from the canopy areas

Painting commenced with the canopy frames that were sprayed with the internal colour mix of Humbrol 78 interior green + white 34 + touch mauve 107. The model was then given a coat of “Halford’s” grey primer (43), although this was not applied over the canopy frames in case the paint reacted (this is what happened to me with the Canberra kit and it is a real nuisance to correct).

(44) Mix of grey 28 and white 34 applied to fuselage sides and upward facing surfaces for ‘pre-highlight”. Notice trailing edges on wings and tail left in primer colour.

A close study of the 601 Sqn photos show a change in paint tone where the underside colour was originally applied, so I decided to include this within my pre-shading. The “Sky” colour is called “Sky (Type S) Gray” by Dupont. Photos (42) indicate that the undersurface is a very pale in tone, lighter than you might expect for the British “Sky” colour, although this could be a characteristic of the primitive digital cameras I guess they had in those days.

I applied white 34 and light grey 28 to the leading edges of horizontal surfaces and to the top and sides of the fuselage both to represent this original under surface colour and also to act as pre-highlight for subsequent colours (44), the bulk of the colour still being left in the “Halfords” grey.

(45) Shading applied to (masked off) fuselage sides and other areas.

The areas of undersurface Sky colour on the fuselage sides were masked off. Grey was sprayed along the sides to represent general shade (45) before the masks were removed to reveal the Sky Type S areas (46).

(46) Masking removed to reveal areas of Sky undersurface

This completed the general pre-shading, but I then did some pre-shading around panel lines. You may notice on real aircraft that dirt which gets caught in panel lines gets pushed downstream during flight and this stains the forward edges of the panel. Therefore, when I apply pre-shade,

I prefer to apply paint by brush along the forward facing edges of the panel (47). I use oil paint for this because it can be made fluid by adding a medium and a mix remains workable for a long time. For these lines I used linseed oil as a medium and it worked fine.

(47) Pre-shading of panel lines applied by paint brush

However, when I did the same thing for the Dark Green panels later in the build it spread out into blotches and looked awful. The better solution would have been to use Liquin and not Linseed oil as the medium, as the Liquin dries quicker and before the colour would have chance to spread.

(48) Pre-shading of panel lines applied by paint brush

For panel lines which are in the direction of flight, I apply the pre-shade to the lowermost side of the panel (or in other words, above the panel line). This is for “arty” effect, to give some contrast between panels, as if the light catches on the top edge of the panel beneath.

This was done along the fuselage, both beneath the air scoop and above the wing root fillet to highlight these features (48).

Camouflage.

(49) MSG applied overall as a transparent coat by airbrush.

The model was airbrushed all over with Xtracolor Medium Sea Grey with 50% Liquin added to give a transparent colour. This was applied on the undersides until the pre-shading was just visible. The upper surfaces had less applied and this was used as a highlight colour for the Mixed Grey camouflage applied next.

The undersides were masked off and a “Mixed Grey” of 7 parts Medium Sea Grey to 1 part black (mixed with 50 % Liquin once again) was airbrushed on – mainly along fuselage sides and the rear of the wings. It was applied to obtain an effect of shading and to get the required contrast with the undersurface colour and pre-shaded panel lines (49). I used loose masks (see Romsey Modeller’s “Hints and Tips” web page for information on these and other ideas for quick ways of masking) to stop the paint that was shading the trailing edges of the wings from going onto the highlighted areas of the fuselage.

(50) Mixed grey masked off and pre-shading of Dark Green areas has been done. The pre-shade went on well, but soon afterwards spread into a blotchy mess as you see here.

Once thoroughly dry (I allowed a week for my paint cocktail to do this), the grey areas were masked off for painting the RAF Dark Green. Humbrol HI 3 was applied as a dark green pre-shade down the fuselage sides. A pre-highlight was done with HI 1 on upwardly facing surfaces. Panel lines were pre-shaded with a dark green oil mix of chrome green + violet blue (which did not go on well because of the linseed oil used as a medium for the oils made the paint spread out like it was applied by a paint spray)(50).

(51) RAF Dark Green applied as transparent coat by airbrush. I was pleased with the way the finish came out, but unfortunately some of the mixed grey peeled off when the masking was removed.

I experimented with various enamel paints and mixes to get a convincing looking RAF Dark Green. In the end, I selected a mix of Precision Paints M514 Field Green (a really old tin of paint!) and HI 3 (and that is quite old as well!) was used to represent RAF Dark Green. This was mixed with 50% Liquin and applied over the pre-shading until the correct contrast was achieved (51).

Now the time to do the fuzzy-edged dark green borders. I don’t have enough skill (or patience) with an airbrush to do it that way. Then I had a eureka moment: if I add linseed oil to my paint mix it will “fuzz-out”, just like it had done for the pre-shading. Simple really. So, I edged the green with an oil mix of chrome green + blue violet + violet red + ivory black with the linseed oil. Did it “fuzz-out” like last time? Like heck it did – it left a strong, sharp edge. Paints are so unpredictable!

The fuselage band was painted next. First with light grey H 28 as an undercoat, then with H 197 Eggshell + H 120 Light Green to get a mix that was approaching the colour of the squadron codes on the decal sheet (52, 53).

(52, 53) Fuselage band airbrushed in after much fussing about with masking tape, liquid masks and polythene bags. Most modellers would do the band first, then the camouflage. I decided not too, because of all the various pre-shading treatments. But it certainly made life more difficult. Notice the band doesn’t wrap around the undersides.

Finishing

With the painting done, now came the time for decaling and painting the panel lines. Two coats of 50% Klear + 50% Windex were applied. This was gradually applied to build up the layers (not flooding on – as this gave me a bad result on my previous build). This was Micromeshed before and between coats.

Photographs of 601 Squadron aircraft show some of the original stencilling was masked off for painting such that the stencilling was left on a rectangle of the original Dupont colouring. To do this, I painted over some spare decals, trimmed them to the right size and then applied them to the model. Once dry, they were given a couple of coats of Klear before the stencil decals were put on.

(54, 55) Background colour for stencils: the Sky (Type S) Gray is a pale grey with a green tint. I mixed Japanese A/N 2 grey with Hu 10 grey. The Dark Earth has a sandier and lighter look to it than RAF Dark Earth. I used WEM RN24 Corticene brown plus light grey. The Dark Green was HU 1 Medium Green.

The paint was airbrushed on until the printed decal markings disappeared. When fully dry, the painted decal was cut by scalpel to the required size and applied to the model like a normal decal.

It is clear from comparing the photos of 601 squadron aircraft to the kit stencil placement guide that (a) many stencils were painted over and (b) the aircraft had stencils in places not shown on the guide.

The decals supplied with the kit are superb: thin, opaque and pull down onto the surface without the need for setting solutions. There was no silvering visible over the micromeshed Klear. They can be tricky to move and I found you needed to use plenty of water to get the decal to lift and reposition. Incidentally, I normally add a drop or two of detergent to the water to reduce its surface tension.

Once fully dried, a final coat of Klear + Windex was applied to seal in the decals. Panel lines were painted in with oil paints, including shades for the decal colours as well. Linseed oil was used to give the paint the required fluidity. Any paint that strayed from the lines can be “pushed back” with a clean brush or wiped with the finger – there should be very little staining of the surrounding area because of the glossy Klear surface. Once the panel line work had thoroughly dried, it was given a light going over with Micromesh 6000 and then airbrushed with Testor’s Dullcote.

(56) The model just prior to the helios incident.

Masking tape was removed from the transparencies without problem. I found problems with the Silly Putty I had used to seal around the door surrounds and a lot of re-work was needed in this area: it had reacted with paint and become firmly stuck in place.

I was now getting towards completion of the kit (56). All the major hurdles were overcome and it would now be plain sailing the short distance to the finishing line.

(57) My modelling area on the patio overlooking the vines and with a view into the long distance of the Provencal countryside. Melissa is hard at work on a jigsaw puzzle whilst I build my Airacobra. It was under this tranquil and idyllic setting that a most heinous event was to unfold.

What could possibly go wrong? Well, the heavens had a different fate in mind. When painting the panel lines outside, in strong sunlight, using a magnifying glass, I had a problem relating to the alignment of the stars. In hind sight, I don’t suppose you had to be clairvoyant to see what would happen: energy from 93 million miles away focussed itself through my 4 inch magnifying glass onto the starboard wing flap of my hapless model, causing it to wilt and distort (57, 58). It was damaged enough for me to consider chucking it and starting something else – but in the end decided to press on and finish the model. My intention now is to put the model into a diorama depicting the highly interesting activity of dragging a tarpaulin across a wing. I haven’t quite figured out why anyone would want to do such a thing, but I’m working on it.

(58) “Do not adjust your sets”. This deformed wing was caused by the heat of sunlight. And some idiot not paying sufficient attention with a magnifying glass. Lucky I didn’t set the table (and Melissa’s jigsaw) on fire at the same time!

My attention now turned towards the detailed parts of the kit. I had deliberately left these until late in the build just in case something went wrong and I had to scrap the kit (!).

Brake lines were added to the main undercarriage legs using the Airacobra I photos as a guide. Then all undercarriage parts were painted in the interior green mix mentioned earlier. This was followed with a coat of Klear and then shading with oils. This is the first time I have tried applying the oils onto a glossy surface (by which I mean it has had just the one coat of Klear, nothing more), and it worked well (59) – I will do this from now on.

(59) Completed work on the undercarriage and wheel wells. The kit parts are well detailed and (after some fiddling) quite strong. The nose doors have photoetched hinges that have a good area of contact for gluing on the door end, but nothing at all on the airframe. I applied a little oil paint as a marker to the hinges and carefully placed them into position against the airframe. I drilled holes where the hinges left their marks and this gave something for the hinges to insert into, making the joint a lot stronger than it would otherwise be.

The brakes on the inside wheel hubs were painted Alclad dark aluminium and followed by an oil wash which settled into the nooks, crannies and crevices of the detail.

(60) Here we can see a couple of devices protruding through the nose panel on the starboard side. These are not in the kit and were scratch made. The small pair of vents behind them are not moulded in, so I represented them by painting. None of these features were present on later versions of the Airacobra.

Tyres can be painted separately from the hubs and assembled later. They do not have any “weighted effect”, so you would need to add this if you want to (I decided not, as my model will be on a grassed diorama and it will not show). I applied a dark grey (Humbrol HM6) over all the tyres and then darkened it with Revell 9 anthracite applied to the tyre walls – leaving the tread area in the lighter colour. After assembly, I ran some black / brown oils around the rim for effect.

The Airacobra I has some curious features on the nose panelling on the starboard side. One item looks like the end of a sanitary fitting and the other a piece of tube. I believe one or the other of them to be undercarriage position indicators (60). Both of these I made from scratch on a modeller’s lathe. These were superglued into place. On the same panel – both on the port and starboard side – are a pair of small vents. Rather than cutting into the plastic, I represented them by painting on shades of grey oil paint.

(61) The crude kit parts for the machine guns were replaced with some from brass rod, drilled and turned down at the end to represent the barrel protruding from the jacket. The Browning .303 had a slotted jacket which was easily and convincingly represented with dashed decal line.

Machine guns supplied in kit look exactly unlike the real thing, so I replaced them with scratch made items from brass rod turned on the lathe. These were undercoated WEM G5 Extra Dark Grey before gluing into position. They were then given an oil paint coat of ivory black mixed with Paynes grey. The paint along the top was then lightly rubbed away with a finger to leave the undercoat showing through as a highlight. This was then reinforced by painting a thin line of titanium white oil paint where the light would be reflected – to one side along the top, at the ends and to highlight the muzzle. Only very tiny amounts of paint were added and then only to places that reflect the light – it is not the same technique as dry-brushing. When the paint had dried, some black dashed line decal from the decals box was run along the highlight to represent the perforated jacket, and I was delighted by the way it turned out (61).

(62) The wing tip lights are separate transparencies in the kit. They are fiddly, but the end result looks good.

(63) There are another pair of navigation lights beneath the wings, and some identification lights which are painted on.

Wing lights are supplied as separate clear parts in the kit. They are very small and need some trimming up once cut from the sprue. I gave mine a coat of Tamiya clear red and green before I cut them. (Red for the left, or port wing. Easy to remember because Port (the drink) is red). I then carefully cleaned up at the end which had been attached to the sprue and stuck the parts upside down onto a blob of Blutack for handling. More Tamiya clear red and green was touched in where needed and then silver was painted over the base surface. These were then superglued in place on the model. The real aircraft has a metal casing over the rear half of the lights so this was undercoated with Lifecolor acrylic white over the Tamiya clear red and green, followed by mixes of grey and green oil paints to match in with the camouflage (62).

There is also an indicator light on each side of the fuselage, just behind the cockpit doors. These are also coloured red and green. The bezels for these are photoetched parts in the kit. They were painted on the fret before being glued into place on the model. The lenses for these – and for three more lights beneath the starboard wing tip – were first blocked in with the acrylic white and then a light (excuse pun) tone of the lens colour, followed by a dark tone of the colour around the periphery. Once this had all dried, a transparent oil mix in a dark colour was applied thinly at the centre and heavier at the border to give the effect of a transparent part (63).

(64) The fuel filler cap was painted and then some wear and tear added, including rubbing marks on the wing from the fueling hoses.

Red coloured circles for the wing fuel caps are provided on the kit decal sheet. However, I preferred to paint the caps instead using an oils mix of Rembrandt permanent red light and violet blue (64).

I used some woven wire mesh (from Little Cars) to represent the back of the various coolers visible up the outlet ducts. These were trimmed to fit using scissors and then painted with Alclad primer. They were then sprayed with Alclad dark aluminium with the outsides dusted up with a light coat of Xtracolor Kuwait Sand (any desert sand colour would do – this was the one that was handy in my paint tray). This was also applied to the ducts, fuselage undersurface and inside of the dampers. The dampers were glued in an open position with plastic rod actuators added (65).

(65) The outlet ducts are quite large and so I thought would benefit from some extra detaining of the radiators. The second photo shows woven wire mesh trimmed to size with scissors. They were then removed and airbrushed with Alcad colours and a sand colour around the peripheries to represent the cooler matrices. They model looks a lot better with them. The dampers are a bit crude in the kit and rather thick in section. I thinned mine down so they looked more like the real article. The actuator rods are from plastic rod.

There are two types of exhaust supplied in the kit. Nearly all of the RAF’s  Airacobra I’s had the wider, fish tail, type fitted. The parts are very nicely shaped, but mine were spoiled by having numerous air bubble holes in the castings. I filled these (or, at least tried to – I was not 100% successful!) with superglue and trimmed to shape.

(66) Exhaust staining along the fuselage was first airbrushed WEM G5 Extra Dark Grey, followed by “Kuwait Sand”. It pays to look at photos to see how much staining is visible and the direction it takes due to air flow. On the real Airacobras, the exhaust staining drops downwards more than I showed on my model.

These were given a coat of Alclad primer followed by Alclad dark aluminium mixed with Alclad Jet Exhaust and Humbrol 171 bronze. Once thoroughly dry, gold printers ink mixed with burnt umber oil paint and linseed oil was brushed all over the exhausts, including inside the outlets. This was rubbed off the upward facing areas which catch the light. Some Kuwait Sand was airbrushed on to represent exhaust staining as a final step, and this was also extended down the fuselage sides after some WEM G5 Extra Dark Grey had been applied first (66).

The radio mast was a good, tight fit to the fuselage. I intended to add an aerial, but as I could not see one (or any insulators, which tend to be more visible) in any of the Airacobra I photographs, I did not do so.

(67) Worn edges from boot damage were done first with a silver pencil on one side of the panel line. I scribbled lines at 90 degrees to the edge as I worked along the panel – varying the height of these much as you might see on a seismograph. For some of the longer “scratches”, I would sometimes leave a space and then add another in line with it. I then used Printer’s Ink mixed with oils to run along the very edge of the panel and further in at corners. The paint has a more intense colour than the pencils and is better for bare metal, rather than “scuffs”. You can also see pastels used for the walking areas on the wing. I used two tones of brown, a darker one first and then a lighter one along the middle of the access way.

Although the RAF Airacobras had only recently been painted in their new camouflage scheme, we know the aircraft had numerous technical problems and so I reckoned there would be some signs of wear and tear. I first used silver pencils to add scuffs to the paint, particularly at corners of panels that I reckoned would see frequent use: engine covers, nose side panels, wing ammunition panels and fuel filler caps. I then followed this with some silver Printer’s Ink mixed with a little Iridescent White oil paint and linseed oil that was added to highlight chipped paintwork (67).

(68) The 20mm cannon was the kit part drilled out and turned in a lathe. It was finished in the same way as the machine guns, albeit without any decals for a perforated jacket. WEN G5 Extra Dark Grey was spattered over the spinner to represent powder stains, this being done for the wing guns as well. Getting WEM paints to spatter, rather than flow freely through an airbrush is quite easy to do. In fact, I find that’s what normally happens.

The model was given a final coat of Testor’s Dullcote to remove any shine from glues or places where the first coat had rubbed down to Klear due to handling.

Final assembly comprised of adding the vulnerable parts: doors, pitot tube and propeller (68). I added three door bolts that were visible in one of the Airacobra I photos, painting these dark grey and highlighting first with Citadel Boltgun metal and then silver Printer’s Ink. The cockpit looks good with the doors fixed in place (69)

(69) The completed cockpit. There is plenty of access to view the detail inside, which adds greatly to the interest of the finished model.

I am very pleased with the way the model has turned out – despite the wilted wing flap – and enjoyed the build. It took longer than I thought, probably because I am slow at painting, but it was always fun and, at times, challenging. I discovered some new ways to do things for the future and some things to never do again. This is only my second 1/32nd aircraft and it seems to be a good scale to work in for small fighters. Whether it is a good scale for bigger models, such as Revell’s
Ju88 (which is in my stash), I will have to see !

The Completed Model


3 Responses to Airacobra Mk I

  1. Joe says:

    Beautiful job! I’ll shamelessly plagerize your techniques.

  2. Graham De Cent says:

    Hi Pat,
    Recently received this kit from Hannants [outstandingly quick service to NZ]. Your write up is inspirational, detailed and simply superb! You have a wonderfull informative way of discribing your building process, with precise and descriptive details. Both building and painting sequences have so much information packed into them. Thank you for sharing this article for all to be inspired to build this kit. I think 1/32 scale is the ideal size for modelling prop driven fighter aircraft as it allows for adequate detail to be shown and the finished size seems ‘ just right ‘.

  3. Pat says:

    Hi Graham and Joe – Many thanks for your kind comments. I hope you enjoy your build of this kit as much as I did!

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