1:72 DAR 12, Bulgarian Air Force Force I/6th Fighter Regiment, 1947

Dizzyfugu · October 05, 2023, 07:17:22 AM

Huzzah! Thanks to the (traditional) deadline extension I was able to cobble another (rather small and simple) submission together, a 1:72 model of the Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947.

Some background:
Darzhavna aeroplanna rabotilnitsa (Държавна аеропланна работилница - State Aircraft Workshops), abbreviated DAR (ДАР), was the first Bulgarian aircraft manufacturer, established in 1924 at Bojourishte. Initially involved in repairing German aircraft then in use in Bulgaria, DAR soon began producing copies of some of these (DAR Uzunov-1, DAR 2), before moving on to licensed production, e. g. the Focke-Wulf Fw 44. The workshops also produced a number of original designs, some of these were produced, while others never proceeded past prototype stage.

One of DAR's most ambitious products was the DAR 12 fighter, a locally modified, license-produced version of the stillborn German Heinkel He 100 fighter. The Heinkel He 100 was a German pre-World War II fighter aircraft design. Although it proved to be one of the fastest fighter aircraft in the world at the time of its development, the design was not ordered into series production. Officially, the Luftwaffe rejected the He 100 to concentrate single-seat fighter development on the competing Messerschmitt Bf 109. Following the adoption of the Bf 109 and Messerschmitt Bf 110 as the Luftwaffe's standard fighter types, the Ministry of Aviation (the Reichsluftfahrtministerium or RLM) announced a "rationalization" policy that placed fighter development at Messerschmitt and bomber development at Heinkel.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

In order to get the best performance out of the aircraft, the He 100 incorporated a number of drag-reducing features. On the simple end was a well-faired cockpit and the absence of struts and other drag-inducing supports on the tail. The landing gear (including the tailwheel) was retractable and completely enclosed in flight. A risky and still experimental method of cooling the engine via evaporative cooling was used, too. Such systems had been in vogue in several countries at the time, and it made a draggy radiator superfluous – in theory, at least, because the closed system was prone to overheating and mechanical failure.

With no perspective to produce the He 100 for the Luftwaffe the basic design was cleared for license production when WWII opened in 1939. Japanese and Soviet delegations visited Heinkel's Marienehe factory on 30 October 1939 and were both impressed by the design. The Soviets were particularly interested in the surface cooling system, having built the experimental Ilyushin I-21 with evaporative cooling themselves. To gain experience with a foreign design they purchased the six surviving He 100 prototypes (V1, V2, V4, V5, V6 and V7), and after arriving in the USSR they were passed on to the TsAGI institute for study. The Japanese were also looking for new aircraft designs, notably those using inline engines with liquid cooling systems, with which they had little experience so far, and purchased the three He 100 D-0s for 1.2 million RM, as well as a license for production and a set of jigs for another 1.6 million RM.

DAR was granted a production license for the airframe, but the He 100's original powerplant, the DB 601, was not part of the deal, as its production was reserved for the Luftwaffe. Nevertheless, the Bulgarian government closed the deal because the He 100 offered a modern high-performance platform. After careful consideration DAR's engineers decided to simplify the aircraft, primarily dispensing with its complex and heavy cooling system, and a different engine was integrated into the He 100's slender airframe. This became a liquid-cooled Hispano-Suiza 12Y engine, which was readily available from Czech license production at Avia.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

Initially, a 12Ycrs with 640 kW/860 PS output was to be used, but on production aircraft it became a more advanced 12Y-26 which offered variable ignition timing, a little more power and could be mated with a three-blade variable pitch propeller from VDA in Germany. The 12Y had less power than the He 100's original DB 601 (876 kW/1,175 hp), but it was lighter, allowed the fitting of an aerodynamic chin radiator that kept the rest of the airframe clean, and it offered the provision for an autocannon with a belt feed to be fitted between the cylinder banks to fire through the propeller hub. With some more simplifications to the airframe and slightly enlarged wing fuel tanks that occupied the former cooling system panels and conduits, this redesigned He 100 became the DAR 12.

The DAR 12 was initially armed with a single 20 mm MG/FF "Motorkanone" and two pairs of light synchronized 7.92 mm (0.312 in) MG 17 machine guns in the wing roots and above the engine, all of German origin. But after only thirty aircraft the wing-mounted weapons were replaced with more powerful 13 mm (.51 in) MG 131 machine guns, which markedly increased the weight of fire and its effective range, and the machine guns above the engine were deleted in favor of an increased ammunition capacity for the MG/FF and a bigger oil tank. Due to the aircraft's small dimensions and dedicated fighter role, no external loads were stipulated.

Once the production lines were running the DAR 12s were directly delivered to the Bulgarian Air Force at the Axis Balkan Front, although some were used by the Luftwaffe for training purposes, too. By 1942, 120 had been delivered. The first 48 DAR 12s were taken over in a ceremony on Karlovo airfield. Two months later, on 24 November, the DAR 12s were used in combat for the first time, when 17 out of the 60 B-24 Liberators of the 15th USAAF arrived over the capital, Sofia, to bomb it. Twenty-four DAR 12s took off from Vrazhdebna base (along with 16 Bf 109G-2s from Bojourishte) and attacked the bombers and their 35 escorting P-38 Lightnings. The Bulgarian pilots claimed four American aircraft for the loss of one fighter, three more had to force land. American bombers attacked Sofia again, on 10 December 1943. That day, 31 B-24s escorted by P-38s, were intercepted by six DAR12s of the II/6th Fighter Regiment from Vrazhdebna and 16 D.520s of the I/6th Fighter Regiment from Karlovo (along with 17 Bf 109G-2s). The Americans claimed eleven victories for the loss of only one P-38, but later examination of records showed that only one Bulgarian aircraft had been lost during that air battle.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

The Bulgarian Air Force DAR 12s were again up in force, to face the massive Allied air raid of 30 March 1944. To intercept the 450 bombers (B-17 Flying Fortresses, B-24s and Handley Page Halifaxes) escorted by 150 P-38s, the Bulgarians scrambled 28 DAR 12s from I./6th at Karlovo, six D.520s from II/6th at Vrazhdebna (together with 39 Bf 109G-6s and even Avia 135s). At least ten Allied aircraft (eight bombers and two P-38s) were shot down, while the Bulgarian Air Force lost five fighters and three pilots. Two more Bulgarian aircraft had to force land.

During the last Allied raid on Sofia, on 17 April, the II./6th fighter scrambled seven DAR 12s (plus 16 Bf 109s), against 350 B-17s and B-24s escorted by 100 P-51 Mustangs. Bulgarian pilots, who up to that time had encountered only P-38s, mistook the P-51s for their own Bf 109s and before they realized their mistake, seven Bf 109G-6s had been shot down. That day the Bulgarian Air Force suffered the heaviest losses since the beginning of the war: nine fighters shot down and three that had to crash land. Six pilots lost their lives. By 28 September 1944, twenty days after Bulgaria joined the Allies, DAR 12s still equipped an Orlyak (Group) of the 6th Fighter regiment.

Although employing a modern design philosophy for its time, the DAR 12 was considered difficult to fly, and even handling on the ground was not easy. Captain Eric Brown, commanding officer of the Royal Aircraft Establishment's Captured Enemy Aircraft Flight, tested a captured DAR 12 at RAE Farnborough, saying that "It was a pretty aircraft, fast and nimble, but also a nasty little brute. Looked beautiful but didn't fly beautifully. And once you got it on the ground, I was told not to leave the controls until it was in the hangar and the engine stopped. You could be taxiing toward the hangar and sit back when suddenly it would go in a right angle."

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

The handling changed markedly according to the amount of fuel carried; using the fuselage tank alone, fuel consumption had no appreciable effect on handling because the tank was at the center of gravity. But with full wing tanks, directional control was compromised, especially in a dive. The original He 100, which had much smaller wing tanks, had not suffered from this problem. On the other side, the flight controls were well harmonized and the aircraft was easy to control at high speed. The maximum dive speed tested was 830 km/h (520 mph) with no buffeting and excellent stability both in the dive and as a gun platform. Overall, the DAR 12 came close to contemporary German types. It was slower than the Bf 109F but superior in maneuverability and had very good roll characteristics. However, once it got out of control it was very hard to stabilize again.

After the war, the Bulgarian Air Force, along with other branches of the Sovietized Bulgarian People's Army, adopted the doctrine of the Soviet deep battle during the Cold War. The surviving DAR 12s were kept in service, but their armament was soon changed to Soviet weapons since ammunition for the German machine guns had become more and more problematic to procure. The 13 mm wing machine guns were replaced with synchronized 20 mm (0.787 in) ShVAK cannon with 150 rpg, while the Motorkanone was deleted (most machines retained the original spinner with the gun muzzle at the tip, though) and the machine guns above the engine were reinstated, now two 12.7 mm (0.50 in) Berezin BS heavy machine guns with 200 rounds each.

In the years directly following the war the Bulgarian Air Force force expanded rapidly with deliveries of different types of combat aircraft, which gradually replaced the worn and outdated wartime types of German, Czech and French origin. The first shipments of Soviet equipment arrived immediately after the end of World War II, mostly consisting of propeller-driven aircraft, such as the Ilyushin Il-2 (120 Il-2 and 10 Il-2U), the Ilyushin Il-10 and the Tupolev Tu-2. By 1954, these types were already being withdrawn from service, as the Korean War marked the beginning of the jet fighter era. In 1955 a new wave of deliveries began, starting with the Mikoyan-Gurevich MiG-15. Around this time, the last DAR 12s in Bulgarian service were retired and scrapped.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

General characteristics:
Crew: One
Length: 8.13 m (26 ft 8 in)
Wingspan: 9.40 m (30 ft 10 in)
Height: 3.60 m (11 ft 10 in) (tail up)
Wing area: 14.60 m2 (157.2 sq ft)
Empty weight: 1,690 kg (3,726 lb)
Gross weight: 2,200 kg (4,850 lb)
Max takeoff weight: 2,500 kg (5,512 lb)
Fuel capacity: 300 kg (660 lb)

Powerplant:
1 × Avia HS 12Y-26 supercharged liquid-cooled 60° V12 engine, delivering 647 kW (900 hp),
driving a 3-bladed VDM constant-speed metal propeller, 2.80 m (9 ft 2 in) diameter

Performance:
Maximum speed: 622 km/h (386 mph; 336 kn) at 5,000 m (16,000 ft)
Cruise speed: 400 km/h (250 mph, 220 kn) at 2,000 m (6,600 ft) and 80% power
Range: 1 765 km (475 mi)
Service ceiling: 10,200 m (33,465 ft)
Time to altitude: 7.0 min to 5,000 m (16,000 ft)

Armament:
2× 20 mm (0.787 in) ShVAK cannon with 150 rpg in the inner wings
2× 12.7 mm (0.50 in) Berezin BS machine guns with 200 rpg above the engine

The kit and its assembly:
This fictional He 100 variant was inspired by a profile drawing I stumbled upon during web research, originally posted at alternatehistory.org, even though I could not find out more about its context or source:

Linked from https://www.alternatehistory.com/forum/threads/better-luck-for-the-he-100.537254/

However, I liked the clean lines and the somewhat vigorous chin radiator – and I had a Special Hobby He 100 kit in store without a concrete plan yet... A matching donor engine could be procured from the KP Avia B.35 kit, of which the rest would immediately find good use for another kitbashing project, so that the decision to take the drawing to the hardware stage in model form was only a small step.

The build was pretty straightforward, but not without prpblems. The He 100 is quite simple, but overall fit is - being a classic short-run model - mediocre at best. The wing halves are pretty thick and leave a rather massive trailing edge, and ejector pins inside have to be sanded away. Fit into the fuselage is also not easy.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) - WiP by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) - WiP by Dizzyfugu, on Flickr

Blending the new engine into the fuselage was also a bit tricky. The respective cut had to be staggered, and the exhaust stubs had to be renewed/scratched. In fact, I blended the new engine into the hull first, because shape and width do not match, and once that was in place I cut out slits for exhaust stubs, leftover from a Heller Spitfire Mk. XVI. Concerning the inspiring profile: as in many cases reality is not as easy as grafting and resizing computer graphics. Beyond shape and width the chin radiator turned out to be much deeper than what graphic artist had envisioned, resulting in a prominent throat sac. As a benfit, though, the radiator outlet now had a natiral opening, and the intake was filled with dark grey foamed styrene to mimic fine mesh. The original retractable radiator underneath the cockpit could simply be omitted. The original He 100 propeller was used, too, it was just mated with a much smaller spinner (from a Heller Bf 109E) and mounted on a metal axis with a matching styrene tube adapter inside the engine housing. The raised propeller position and the prominent chin radiator change the profile markedly, but it does not look bad at all!

Cockpit and landing gear were taken OOB. A nice feature of the He 100 is the extensive but reasonable use of PE parts, e. g. for the landing gear covers. There are few kits which I know where the use of this material makes so much sense, and it even works well and helps to maintain the He 100's slender, if not filigree, look.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) - WiP by Dizzyfugu, on Flickr

Painting and markings:
While the Bulgarian Air Force was quickly settled upon as the operator for this fictional aircraft, finding a suitable livery and markings were a bit tricky. I did not want to create a WWII Axis Forces machine, and then remembered a Blue Rider set of decals for Bulgarian machines from direct post-war era in my stash. It contained so-called "OF" markings, quite exotic red-and-white roundels with green bars that were only carried for three years before Soviet-style Red Stars were introduced in Bulgaria. With this time frame defined, I used a Bulgarian post-war Bf 109G as benchmark and adapted its paint scheme for the Bulgarian post-war DAR 12.

Bulgarian post-war aircraft typically carried a uniform dark-green livery with light blue undersides - quite simple and dull. However, the specific benchmark Bf 109 carried remnants of its former Luftwaffe livery, most visible on the flanks which had had a high waterline and some grey mottles. For the DAR 12 I adapted this idea and gave the model a basic late war Luftwaffe camouflage consisting of RLM 81, 83 and 76. Former yellow wing tips and a fuselage band were overpainted with a slightly different shade of light blue. On top of that I gave the aircraft a uniform dark green coat - I could not find credible information concerning the tone, so that I went with RAL 6031 (Bronzegrün), which has a yellowish hue to it. I used thinned Revell 65, applied in a streaky manner with a flat brush, so that the Luftwaffe colors underneath would shine through here and there. This was later enhanced with a careful wet sanding treatment. The interior surfaces were painted with RLM02.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) - WiP by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) - WiP by Dizzyfugu, on Flickr

The kit received an overall washing with thinned black ink and some post-shading for more variety and weathering. The roundels came from the aforementioned Blue Rider decal sheet, which also provided material for the tricolor fin markings. The tactical code number came from a Hobby Boss MiG-15, and some stencils were added, left over from an Academy Fw 190D. After some final weathering with silver and grinded graphite around the exhaust stubs the model was sealed with matt acrylic varnish, and as final steps a wire antenna (made from heated black sprue material) as well as cannon barrels on the wings (hollow steel needles) were added.

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

1:72 Darzhavna Aeroplanna Rabotilnitsa DAR 12; 'White 4' of the Bulgarian Air Force I/6th Fighter Regiment, Karlovo air base (Plowdiw Oblast, Central Bulgaria), 1947 (Whif/modified Special Hobby kit) by Dizzyfugu, on Flickr

A relatively quick build and conversion, even though the new engine was not as easy to integrate as expected. The result looks nice, though. While the He 100's elegance (and much of its semblance!) is gone thorugh this small change the aircraft still looks fast and purposeful - and the prominent chin radiator makes it look like a juvenile Hawker Tempest Mk. V or a diminuitive late Curtiss P-40?

NARSES2 · October 06, 2023, 06:10:07 AM

I like that

Wardukw · October 06, 2023, 08:22:01 AM

That looks like a normal Dizzy build to me to be honest ..very cool 😁.

Old Wombat · October 07, 2023, 01:20:54 AM

I knew I recognised the engine from something Czech!

Be interesting to see what happens to the B.35

Dizzyfugu · October 07, 2023, 03:09:55 AM

Quote from: Old Wombat on October 07, 2023, 01:20:54 AMBe interesting to see what happens to the B.35

It already has - it became my 3rd Avro Swallow some time ago (with a Merlin and a new landing gear)!

1:72 Avro 675 'Swallow' PR Mk. II trop.; '(GA-)E/N8187' of the Royal Air Force No. 208 Squadron; RAF Gaza air base (Palestine), late 1941 (Whif/KP Models Avia B.35 conversion) by Dizzyfugu, on Flickr

su27rules · October 07, 2023, 03:44:45 AM

Bravo!!

Old Wombat · October 07, 2023, 04:11:43 AM

Quote from: Dizzyfugu on October 07, 2023, 03:09:55 AM
Quote from: Old Wombat on October 07, 2023, 01:20:54 AMBe interesting to see what happens to the B.35

It already has - it became my 3rd Avro Swallow some time ago (with a Merlin and a new landing gear)!

1:72 Avro 675 'Swallow' PR Mk. II trop.; '(GA-)E/N8187' of the Royal Air Force No. 208 Squadron; RAF Gaza air base (Palestine), late 1941 (Whif/KP Models Avia B.35 conversion) by Dizzyfugu, on Flickr

Sneaky!

She looks good!

tomo pauk · January 06, 2024, 01:43:30 AM

Most excellent, I'm glad that the profile gained a new life through your work and dedication