1:72 Bell P-39Q, RNZAF 14 Squadron, Gualdalcanal, 1943

[Dizzyfugu]

1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr



Some background:
The Bell P-39 Airacobra was a fighter produced by Bell Aircraft produced for the U.S. Army Air Forces during World War II. It was one of the principal American fighters in service when the United States entered combat. It had an unusual layout, with the engine installed in the center fuselage, behind the pilot, and driving a tractor propeller in the nose with a long shaft. Although its mid-engine placement was innovative, the P-39 design was handicapped by the absence of an efficient turbo-supercharger, preventing it from performing high-altitude work, and it only had a limited fuel capacity. For this reason, it was rejected by the RAF for use over western Europe but adopted by the USSR, where most air combat took place at medium and lower altitudes.

The P-39 was an all-metal, low-wing, single-engine fighter, with a tricycle undercarriage and an Allison V-1710 liquid-cooled V-12 engine mounted in the central fuselage, directly behind the cockpit. The Airacobra was one of the first production fighters to be conceived as a "weapons system"; in this case the aircraft (known originally as the Bell Model 4) was designed to provide a platform for the 37 mm (1.46 in) T9 cannon. This weapon, which was designed in 1934 by the American Armament Corporation, a division of Oldsmobile, fired a 1.3 lb (0.59 kg) projectile capable of piercing .8 in (20 mm) of armor at 500 yd (460 m) with armor-piercing rounds. The 90 in (2,300 mm)-long, 200 lb (91 kg) weapon had to be rigidly mounted and fire parallel to and close to the centerline of the new fighter. The complete armament fit consisted of the T9 cannon with a pair of Browning M2 .50 in (12.7 mm) machine guns mounted in the nose. This changed to two .50 in (12.7 mm) and two .30 in (7.62 mm) guns in the XP-39B (P-39C, Model 13, the first 20 delivered) and two .50 in (12.7 mm) and four .30 in (7.62 mm) (all four in the wings) in the P-39D (Model 15), which also introduced self-sealing tanks and shackles (and piping) for a 500 lb (230 kg) bomb or drop tank.


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


It would have been impossible to mount the weapon in the fuselage, firing through the cylinder banks of the Vee-configured engine and the propeller hub as could be done with smaller 20mm cannon. Weight, balance and visibility considerations meant that the cockpit could not be placed farther back in the fuselage, behind the engine and cannon. The solution adopted was to mount the cannon in the forward fuselage and the engine in the center fuselage, directly behind the pilot's seat. The tractor propeller was driven with a 10-foot-long (3.0 m) drive shaft made in two sections, incorporating a self-aligning bearing to accommodate fuselage deflection during violent maneuvers. This shaft ran through a tunnel in the cockpit floor and was connected to a gearbox in the nose of the fuselage which, in turn, drove the three- or (later) four-bladed propeller by way of a short central shaft. The gearbox was provided with its own lubrication system, separate from the engine; in later versions of the Airacobra the gearbox was provided with some armor protection.

The glycol-cooled radiator was fitted in the wing center section, immediately beneath the engine; this was flanked on either side by a single drum-shaped oil cooler. Air for the radiator and oil coolers was drawn in through intakes in both wing-root leading edges and was directed via four ducts to the radiator faces. The air was then exhausted through three controllable hinged flaps near the trailing edge of the center section. Air for the carburetor was drawn in through a raised oval intake immediately aft of the rear canopy. Because of the unconventional layout, there was no space in the fuselage to place a fuel tank. Although drop tanks were implemented to extend its range, the standard fuel load was carried in the wings, with the result that the P-39 was limited to short-range tactical strikes.

The fuselage structure was unusual and innovative, being based on a strong central keel that incorporated the armament, cockpit, and engine. Two strong fuselage beams to port and starboard formed the basis of the structure. These were angled upwards fore and aft to create mounting points for the T9 cannon and propeller reduction gearbox and for the engine and accessories respectively. A strong arched bulkhead provided the main structural attachment point for the main spar of the wing. This arch incorporated a fireproof panel and an armor plate between the engine and the cockpit. It also incorporated a turnover pylon and a pane of bullet-resistant glass behind the pilot's head. The arch also formed the basis of the cockpit housing; the pilot's seat was attached to the forward face as was the cockpit floor. Forward of the cockpit the fuselage nose was formed from large removable covers. A long nose wheel well was incorporated in the lower nose section – the Airacobra was the first fighter fitted with a tricycle undercarriage. The engine and accessories were attached to the rear of the arch and the main structural beams; these too were covered using large removable panels. A conventional semi-monocoque rear fuselage was attached aft of the main structure.


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


Because the pilot was above the extension shaft, he was placed higher in the fuselage than in most contemporary fighters, which in turn gave the pilot a good field of view. Access to the cockpit was by way of sideways opening "car doors", one on either side. Both had wind-down windows. As only the right-hand door had a handle both inside and outside, this was used as the normal means of access and egress. The left-hand door could be opened only from the outside and was for emergency use, although both doors could be jettisoned. In operational use, as the roof was fixed, the cockpit design made escape difficult in an emergency.

The Airacobra saw combat throughout the world, particularly in the Southwest Pacific, Mediterranean and Soviet theaters. In both western Europe and the Pacific, the Airacobra found itself outclassed as an interceptor and the type was gradually relegated to other duties. It often was used at lower altitudes for such missions as ground strafing. Beyond the USAAF and the USSR, other major users of the type included the Free French, the Royal Air Force, and the Italian Co-Belligerent Air Force. Minor operators were Australia, the Netherlands (the ML-KNIL) and New Zealand.

In 1942, the threat of attack seemed real: the city of Darwin was bombed, New Guinea was invaded, and Japanese reconnaissance aircraft overflew Auckland and Wellington. The New Zealand Government hurriedly formed 488 Squadron's pilots, battle-experienced from the fall of Singapore in February 1942, into the RNZAF's first active fighter unit: No. 14 Squadron. The unit was established under Squadron Leader John MacKenzie at Masterton on 25 April 1942, equipped with North American Harvards, a handful of P-40 Kittyhawks and leftover Brewster Buffaloes from the disbanded 488 Squadron, and with 23 re-conditioned P-39D Airacobras, on loan from the U.S. Fifth Air Force (5 AF) after having been repaired in Australia. The Airacobras were initially used by the Royal New Zealand Air Force (RNZAF) as a stop-gap interceptor in rear areas until more P-40s could be obtained, but the lack of first-line aircraft soon forced them into battle.


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


The Allied plan was for the Americans to defeat the Japanese by island hopping north across the Pacific. This plan involved bypassing major Japanese bases, which would continue to operate in the allied rear. The RNZAF was given the job of operating against these bypassed Japanese units. At first, maritime patrol and bomber units moved into the Pacific, followed by 15 Squadron with Kittyhawks. In April 1943, a year after forming, 14 Squadron moved to the rear base at Espiritu Santo to resume action against the Japanese. The unit was now primarily equipped with P-40s, which became the primary RNZAF fighter of the era. But 14 Squadron also received thirty-six new P-39Qs, too, which had the wing-mounted pairs of 0.30 in (7.62 mm) machine guns replaced with a 0.50 in (12.7 mm) with 300 rounds of ammunition in a pod under each wing and 231 lb (105 kg) of extra armor. Due to their limited performance at altitude and their tendency to stall in a tight turn and possibly go into a flat spin (due to the engine behind the center-of-gravity), which many a pilot did not recover from, the P-39s were primarily used for ground attack and reconnaissance missions, and against naval targets close to the shorelines, e .g. troopships.
For the remainder of the war, 14 Squadron rotated between forward and rear bases in the Pacific and 6-week periods of home leave in New Zealand. On 11 June 1943, 14 Squadron moved to the forward base of Kukum Field on Guadalcanal—on its first contact with the enemy, the following day, six Japanese aircraft were destroyed. The squadron later deployed to different bases in the South Pacific as demanded: In November 1943, 14 Squadron moved for the first time to New Georgia, followed by Bougainville in February 1944, Green Island in December, and Emirau in July 1945. In 1944, No. 14 Squadron became one of thirteen RNZAF squadrons re-equipped with Vought F4U Corsairs, which replaced all remaining P-39s. By this time the Japanese fighters had been all but eliminated and the unit increasingly attacked ground targets.


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr


1:72 Bell Model 26Q P-39Q-1 "Airacobra"; aircraft "HQ-K/NZ 3220" of the Royal New Zealand Air Force No. 14 Squadron; Kukum Airfield, Guadalcanal; July 1943 (What-if/Hobby Boss kit) by Dizzyfugu, on Flickr







General characteristics:
    Crew: One
    Length: 30 ft 2 in (9.19 m)
    Wingspan: 34 ft 0 in (10.36 m)
    Height: 12 ft 5 in (3.78 m)
    Wing area: 213 sq ft (19.8 m²)
    Empty weight: 6,516 lb (2,956 kg)
    Gross weight: 7,570 lb (3,434 kg)
    Max takeoff weight: 8,400 lb (3,810 kg)

Powerplant:
     1× Allison V-1710-85 V-12 liquid-cooled piston engine, delivering 1,200 hp (890 kW) at 9,000 ft (2,743 m) at emergency power, driving a 3-bladed constant-speed propeller

Performance:
    Maximum speed: 389 mph (626 km/h, 338 kn)
    Stall speed: 95 mph (153 km/h, 83 kn) power off, flaps and undercarriage down
    Never exceed speed: 525 mph (845 km/h, 456 kn)
    Range: 525 mi (845 km, 456 nmi) on internal fuel
    Service ceiling: 35,000 ft (11,000 m)
    Rate of climb: 3,805 ft/min (19.33 m/s) at 7,400 ft (2,300 m), using emergency power
    Time to altitude: 15,000 ft (4,600 m) in 4 minutes 30 seconds, at 160 mph (260 km/h)
    Wing loading: 34.6 lb/sq ft (169 kg/m²)
    Power/mass: 0.16 hp/lb (0.26 kW/kg)

Armament:
    1× 37 mm (1.5 in) M4 cannon with 30 rounds, firing through the propeller hub
    4× 0.5 in (12.7 mm) Browning M2 machine guns,
          two synchronized with 200 RPG in the nose, one with 300 RPG under each outer wing
     1× ventral hardpoint for up to 500 lb (230 kg) of bombs or a drop tank



The kit and its assembly:
This was a quick project, a simple "livery whif" based on a profile drawing of a fictional RNZAF P-39, created by fellow board member PantherG here at whatifmodellers.com and published in June 2021:




Since the fictional livery aspect of this build would be the centerpiece, I chose the cheap and simple Hobby Boss P-39 kit from 2007 as basis. There are two Hobby Boss kits of the P-39: an N and a Q boxing, but both are identical and only differ through the decals. To build an N, you leave away the underwing gun pods, and for a Q you cut away the machine gun barrels from the wings.

The kit is rather primitive and sturdy, but it still needs some PSR around the fuselage seams. However, from the outside the Hobby Boss kit is a decent representation of a P-39 – if you want a (really) quick build and/or you are on a budget, it's O.K. The kit was built OOB, I just added a pilot figure to the (primitive) cockpit with seat belts made from masking tape, since this would be the only detail inside to be recognizable, and I added a radio set behind the seat to fill the empty space above the engine cover. The openings for the fuselage-mounted machine guns had to be carved into the hull. I used the OOB propeller mount with its thin steel axis, because it is more compact than my own usual styrene tube arrangement – the leftover space in the nose was filled with lead to keep the front wheel on the ground. However, the literally massive tail of the model necessitated even more nose weight, so that the front landing gear well was partly filled with lead, too. Not pretty, but the lead beads are only visible directly from below – and it was eventually enough to keep the nose down!








Painting and markings:
This model is not a 1:1 hardware rendition of PantherG's drawing, rather a personal interpretation of the idea that the RNZAF had operated the P-39 in the PTO around 1943. However, I took over the basic USAAF livery in overall Olive Drab 41 with Neutral Grey 43 (FS 36173) undersides, plus generous Medium Green 42 (~FS 34094) contrast blotches on the edges of the aerodynamic surfaces to break up the aircraft's outlines.
The paints became Tamiya XF-62 (IMHO the best rendition of the USAAF tone) with Humbrol 105 (FS 34097) for the additional wing cammo, and Humbrol 165 (RAF Medium Grey, a lighter tone than Neutral Grey) underneath. 105 was chosen because it gives a good contrast to the Olive Drab background, and it is not too bluish. The cockpit interior and the landing gear wells were painted in zinc chromate green - Humbrol 159 was used.

A black ink washing and some post-panel-shading followed, with stronger weathering on the upper surfaces to simulate sun-bleaching. The markings are roughly based on a contemporary RNZAF P-40M, and it is a wild mix. The ex-USAAF camouflage would not be used by the RNZAF, but the white ID bands on wings and fuselage as well as the white spinner are typical for the time. The same goes for the roundels, which still contained tiny red discs at the fuselage roundels' center. Oddly, very different roundels were carried above and below the wings. As a repaired and re-badged ex-USAAF aircraft, I added overpainted markings of this former operator – the serial number on the fin as well as the former bars of the American markings were painted over with (a sort of) Foliage Green (Humbrol 172).



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The national markings, the serial number and the small nose art came from a Rising Decals sheet for various RNZAF aircraft types, while the white stripes were improvised with generic decal sheet material (TL Modellbau). The RAF-style tactical code was not carried by the RNZAF's machines, but I added them, anyway, because they might have been left over from early RNZAF operations. However, together with the white ID bands, there's a lot going on along the fuselage – white code letters would certainly have been "too much". The code letters in Medium Sea Grey came from an Xtradecal sheet, and due to the little space on the rear fuselage the unit code "HQ" was placed on the nose – in a fashion similar to the RAAF's few P-39s.

After a light black ink washing and some post shading and weathering (e. g. exhaust stains with graphite), the model was sealed with matt acrylic varnish and wire antennae from heated sprue material added.












Well, from the construction perspective, this was a very simple project, and despite the Hobby Boss kit's basic constriction, the result looks quite good. Even the canopy – normally a weak spot of these kits – looks decent. And I was lucky that I could cramp enough weight into the nose space that the model actually rests on all of its wheels. The camouflage is not spectacular, either, just the markings, esp. the ID bands, caused some headaches, but thanks to generic white decal stripes even such details lose their horror. A nice-looking what-if Airacobra, and I feel inclined to create a contemporary ML-KNIL machine someday, too.

[Doug K]

Excellent, the scheme suits the airframe

[stevehed]

Like it, very imaginative. Love the markings.

[Tophe]

good model, good pictures

[Dizzyfugu]

Thank you!

[kitbasher]

 

I like the Hobbyboss P-39, a handy basis of a quick build (and it takes two Jumos with no difficulty at all!).  Must get another for another whif - like yours a change of markings, nothing difficult.

[NARSES2]

That's very nice Dizzy 

The RNZAF in the SW Pacific offers loads of opportunities for both types of aircraft used and markings they were adorned with. Mainly because they seemed to be last in the "pecking order" when it came to getting new equipment and they used so many different styles of markings.

They'll be getting a Tempest II when the KP kit comes out 

[Dizzyfugu]

They'll be getting a Tempest II when the KP kit comes out 

I was recently tempted to do a Tempest (probably a II) in SEAC markings, should look quite cool, too. 

[NARSES2]

They'll be getting a Tempest II when the KP kit comes out 

I was recently tempted to do a Tempest (probably a II) in SEAC markings, should look quite cool, too. 

That's another one I have planned