+++ DISCLAIMER +++
Nothing you see here is real, even though the conversion or the presented background story might be based historical facts. BEWARE!
Some background:
Due to increasing tensions in Europe which led to World War 2, AVRO Aircraft started developing combat aircraft, and as a subsidiary of Hawker, they had access to the Hurricane plans. At the time that the Hurricane was developed, RAF Fighter Command consisted of just 13 squadrons, each equipped with either the Hawker Fury, Hawker Demon, or the Bristol Bulldog – all of them biplanes with fixed-pitch wooden propellers and non-retractable undercarriages. After the Hurricane's first flight, Avro started working on a more refined and lighter aircraft, resulting in a similar if not higher top speed and improved maneuverability.
The result was Avro’s project 675, also known as the "Swallow". The aircraft’s profile resembled the Hawker Hurricane, but appeared more squatted and streamlined, almost like a race version. Compared with the Hurricane, overall dimensions were reduced and the structure lightened wherever possible. The wings were much thinner, too, and their shape reminded of the Supermarine Spitfire’s famous oval wings. The main landing gear was retractable and had a wide track. The tail wheel was semi-retractable on the prototype, but it was later replaced by a simpler, fixed tail wheel on production models.
The Swallow made its first flight on 30th December 1937 and the Royal Air Force was so impressed by its performance against the Hurricane that they ordered production to start immediately, after a few minor tweaks to certain parts of the aircraft had been made.
On 25 July 1939, the RAF accepted their first delivery of Avro Swallow Mk. Is. The first machines were allocated to No.1 Squadron, at the time based in France, where they were used in parallel to the Hurricanes for evaluation. These early machines were powered by a 1.030 hp (770 kW) Rolls-Royce Merlin Mk II liquid-cooled V-12, driving a wooden two-bladed, fixed-pitch propeller. The light aircraft achieved an impressive top speed of 347 mph (301 kn, 558 km/h) in level flight – the bigger and heavier Hurricane achieved only 314 mph (506 km/h) with a similar engine. Like the Hurricane, the Swallow was armed with eight unsynchronized 0.303 in (7.7 mm) Browning machine guns in the outer wings, outside of the propeller disc.
In spring 1940, Avro upgraded the serial production Swallow Mk.I's to Mk.IA standard: the original wooden propeller was replaced by a de Havilland or Rotol constant speed metal propeller with three blades, which considerably improved field performance. Many aircraft were retrofitted with this update in the field workshops until summer 1940.
In parallel, production switched to the Swallow Mk. II: This new version, which reached the front line units in July 1940, received an uprated engine, the improved Rolls-Royce Merlin III, which could deliver up to 1,310 hp (977 kW) with 100 octane fuel and +12 psi boost. With the standard 87 Octane fuel, engine performance did not improve much beyond the Merlin II's figures, though.
A more streamlined radiator bath was fitted, too, and altogether these measures boosted top speed to 371 mph (597 km/h) at 20,000 ft (6,096 m). This was a considerable improvement, and the contemporary Hurricane II achieved only 340 mph (547 km/h).
Despite this improvement, though, several fundamental weak points of the Swallow remained unsolved: its limited range could not be boosted beyond 300 miles (500 km) and the light machine gun armament remained unchanged, because the Swallow’s thin wings hardly offered more space for heavier weapons or useful external stores like drop tanks.
Despite these shortcomings, the pilots loved their agile fighter, which was described as an updated Hawker Fury biplane fighter and less of a direct competitor to the Hurricane. After War had been declared, the crews flew the early Mk.I well against the more experienced Luftwaffe fighters, and many of these aircraft were updated to Mk. IA standard.
Since the type was not operated in large numbers, Swallow aces were few. One of them was Flight Lieutenant Killian Murphy, an Irish Volunteer and Pilot of JX-M of RAF No. 1 Squadron. He scored two of his total 24 kills in a Mk. I, and 8 more in a Mk. II from August 1940 on. The initial scores were a Bf 109E and a Ju87, both shot down during the evacuation of Dunkirk. Most of his later victories were scored during the defense of London, before the squadron was completely re-equipped in early 1941 with Hurricane Mk. IIs and later Typhoons, rather focusing on ground attack and interdiction missions on Continental Europe.
Some work was done to improve the Swallow, but with limited success. For instance, in early 1941 a Swallow Mk. II was modified to carry a pair of 20mm Hispano cannons instead of the inner pair of machine guns. Due to the thin wings, this option necessitated bulged fairings and a modified internal structure for the cannons' ammunition drums, but the additional firepower was welcomed and led to the Swallow Mk. III, which was introduced in August 1941. It was the final production variant, still powered by the Rolls-Royce Merlin III from the swallow Mk. II. Beyond the armament changes, the wing tips were clipped in order to improve roll characteristics at low and medium altitude. Otherwise the Mk. III was virtually identical to the earlier Mk. II.
Another Mk. II was experimentally converted with a lowered spine and a framed bubble canopy (reminiscent of the Hawker Typhoon's design), but this experiment did not reach production status. The Swallow had already reached its limited development potential.
Since the Supermarine Spitfire had in the meantime proven its worth and promised a much bigger development potential, production of the Avro Swallow already ceased in late 1942 after 435 aircraft had been built. Around the same time, the Swallow was quickly phased out from front-line service, too.
Several machines were retained as trainers, messenger aircraft or instructional airframes. 20 late production Mk. IIs were sold to the Irish Air Corps, and a further 50 aircraft were sent to Canada as advanced fighter trainers, where they served until the end of the hostilities in 1945.
General characteristics:
Crew: 1
Length: 8.57 m (28 ft 1 in)
Wingspan: 10.85 m (35 ft 7 in)
Height: 2.60 m (8 ft 6 in)
Wing area: 17.00 m² (183 ft²)
Empty weight: 1,690 kg (3,726 lb)
Gross weight: 2,200 kg (4,850 lb)
Powerplant:
1× Rolls-Royce Merlin III liquid-cooled V-12, rated at 1,310 hp (977 kW) at 9,000 ft (2,700 m)
Performance:
Maximum speed: 371 mph (597 km/h) at 20,000 ft (6,096 m)
Range: 320 miles (515 km)
Service ceiling: 36,000 ft (10,970 m)
Rate of climb: 2,780 ft/min (14.1 m/s)
Wing loading: 29.8 lb/ft² (121.9 kg/m²)
Power/mass: 0.15 hp/lb (0.25 kW/kg)
Armament:
8× 0.303” (7,7mm) Browning machine guns with 350 RPG in the outer wings
The kit and its assembly:
Another entry to the Battle of Britain Group Build at whatifmodelers.com, and this time a collaboration. This fictional machine – or better: the model – is based on a 2D profile conceived by fellow forum member nighthunter: an Avia B.135, outfitted with a Merlin engine, a ventral radiator in the style of a Hawker Hurricane, and carrying RAF markings.
Since I had a spare B.35 sans engine left over from the recent Fokker D.XXIII conversion, I used the opportunity to take the virtual design to the hardware stage!
The basis is a vintage KP Models kit of the early B.35 fighter with a fixed landing gear. It’s a sleek and pretty aircraft, but the kit’s quality is rather so-so. Details are good, you get a mix of engraved and raised surface details, but fit is mediocre and there is lots of flash. But, with some effort, things can be mended.
Many donation parts for the Swallow, including the engine, propeller, landing gear and radiator, come from an AZ Models Spitfire Mk. I/II/V, from a recently bought Joy Pack which comes with three of these kits without decals.
New landing gear wells had to be drilled into the massive lower wing halves. Since the original Swallow profile did not indicate the landing gear design, I went for an inward-retracting solution, using parts from an early Spitfire. Due to the oil cooler in one of the wing roots, though, the stance ended up a little wide… The Merlin fitted very well onto the B.35 fuselage, and, inside of the cockpit, I added a tank behind the seat in order to fill the OOB void there.
Another internal change I made is the installation of my trademark propeller adapter: a styrene tube inside of the fuselage that holds a long metal axis with the propeller, so that it can spin freely.
Painting and markings:
Very conservative, but IMHO a good match for this fictional fighter: Standard RAF colors in Dark Green/Dark Earth (both enamels from the Modelmaster Authentic line), nothing fancy, and I had the profile as benchmark for what I wanted to achieve. Since the plane is placed historically in August 1940, Sky was about to be introduced, but only gradually and sometimes with “different” tones. Therefore, I painted the underside with Humbrol 23, Duck Egg Blue, and also added roundels under the wings.
The code letters should have been Medium Sea Grey, but the profile showed white letters – so I stuck with that, and AFAIK there had been exceptions to the rule. The code letters came from an Xtradecal RAF white letter sheet. Roundels and fin flash come from various sources, including a Matchbox Brewster Buffalo and a Trumpeter P-40C. The serial number was improvised, too.
As personal markings I painted a green shamrock under the cockpit on port side, while a list of air combat scores came under the starboard cockpit side (in style with the original profile). A green ring on the spinner was added, too, inspired by the real world No. 1 Squadron’s JX-B, flown by Arthur Clowes. His machine carried a bee nose art and a yellow spinner ring: for every victory, the bee would receive a new stripe, and he achieved eight during his career.
Some light weathering and panel shading was done, as well as some light soot stains around the exhausts and the gun ports on the wings. Finally, everything sealed under a coat of matt acrylic varnish (Revell), which unfortunately turned white in some seams! :-/
The Avro Swallow looked already promising in nighthunter's profile, almost like a missing link between the sturdy Hurricane and the more glorious Spitfire.
A quick build, but a conversion that has to be kept in mind, because the result looks so convincing! Seeing the completed aircraft, I am amazed how good this thing looks overall, with its elegant, oval wings and the sleek fuselage lines. Nice one! :D
