All posts by Gunther Arnold

Medium Bomber

Douglas XB-43 “Jetmaster” (Anigrand, Resin)

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TYPE: High-speed medium bomber

ACCOMMODATION: Crew of three

POWER PLANT: Two General Electric J35-GE-3 turbojet engines, rated at 1,835 kp each

PERFORMANCE: 507 mph

COMMENT: USAAF leaders in the Air Material Command began to consider the possibilities of jet-propelled bombers as far back as October 1943. At that time, Douglas Aircraft was just beginning to design a promising twin-engine bomber designated the XB-42 “Mixmaster”. Reciprocating engines powered this aircraft but they were buried in the fuselage, leaving the laminar flow-airfoil wing clean of any drag-inducing pylon mounts or engine cowlings. The airframe appeared ideally suited to test turbojet propulsion. Douglas confirmed the feasibility of the concept and the USAAF amended the XB-42 contract in March 1944 to include the development of two turbojet-powered XB-43 prototypes, reduced from an initial order of 13 test aircraft. The Douglas design team convinced the Army that modifying the XB-42 static test airframe into the first XB-43 was a relatively straightforward process that would save time and money compared to developing a brand new design. Douglas replaced the two Allison V-1710 engines with a pair of General Electric J35 turbojets, then cut two air intakes into each side of the fuselage, aft of the pressurized cockpit. Removing the propellers and drive shafts freed enough space for two long jet exhaust ducts. Without any propellers present, there was no chance of striking the blade tips on the runway, so the entire ventral fin/rudder unit of the earlier XB-42’s full four-surface cruciform tail was omitted. Douglas compensated for the loss of yaw stability by enlarging the dorsal fin/rudder unit. The end of World War II caused a general slowdown within the aviation industry and General Electric was late delivering the engines. So America’s first turbojet bomber finally flew for the first time on 17 May 1946. Douglas Aircraft was keen to mass-produce the new bomber and the USAAF considered ordering 50, but these plans never became realized. The USAAF was already moving ahead with a new bomber, the North American XB-45 “Tornado”, designed from the outset for turbojet power and promising a quantum leap in every category of performance (Ref.: 24).

Medium Bomber

Douglas XB-42 “Mixmaster” (Anigrand, Resin)

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TYPE: High-speed medium bomber

ACCOMMODATION: Crew of three

POWER PLANT: Two Allison V-1710-125 liquid-cooled engine, rated at 1,325 hp each, driving three-bladed, contra-rotating propellers

PERFORMANCE: 410 mph at 23,440 ft

COMMENT: The XB-42 was developed initially as a private venture; an unsolicited proposal was presented to the USAAF in May 1943. This resulted in a contract for two prototypes and one static test airframe, the USAAF seeing an intriguing possibility of finding a bomber capable of the Boeing B-29 “Superfortress” range without its size or cost. The aircraft mounted a pair of Allison V-1710-125 liquid-cooled V-12 engines behind the crew’s cabin, each driving one of the twin propellers. Air intakes were in the wing leading edge. The landing gear was tricycle and a full, four surface cruciform tail was fitted, whose ventral fin/rudder unit prevented the coaxial propellers from striking the ground. The pilot and co-pilot sat under twin bubble canopies, and the bombardier sat in the extreme front behind a plexiglass nose. Defensive armament was two 0.50 in machine guns each side in the trailing edge of the wing, which retracted into the wing when not in use. These guns were aimed by the copilot through a sighting station at the rear of his cockpit. The guns had a limited field of fire and could only cover the rear, but with the aircraft’s high speed it was thought unlikely that intercepting fighters would be attacking from any other angle. The first XB-42 was delivered to the Army Air Force and flew at on 6 May 1944. Performance was excellent, being basically as described in the original proposal: as fast or even faster than the de Havilland “Moquito” but with defensive armament and twice the bomb-load. The end of World War II allowed the Air Force to consider possibilities with a little more leisure. Although with the second prototype additional Westinghouse 19XB-2A jet engines were mounted under the wings to enhance performance (XB-42A) it was decided to wait for the development of better jet bombers rather than continue with the XB-42 program (Ref.: 24).

Projects

Douglas DS-312A (Unicraft, Resin)

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TYPE: Experimental pusher fighter. Project

ACCOMMODATION: Pilot only

POWER PLANT: One Allison V-1710 liquid-cooled engine, rated at 1,100 hp at 30,000ft, driving contra-rotating propellers via extension shaft

PERFORMANCE:  Data not available

COMMENT: Work on this unusual design started in in 1939. In order to keep the fuselage aerodynamically as clean as possible the engine was mounted in the mid-fuselage, driving counter-rotating three bladed pusher propellers via an extension shaft. Another advantage of the buried engine was enough room for heavy cannon armament in the nose. Thus the pilot had an excellent view and a wide field of fire. Although this fighter project was never realized it was the basis for many other pusher-type aircraft e.g. Bell XP-52, Vultee XP-54 Swoose Goose, Curtiss-Wright XP-55 Ascender, Northrop XP-56 Black Bullet, and Douglas XB-42 Mixmaster.

Fighter, Projects

Hawker P.1048 (Unicraft, Resin)

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Type: Two Turbojets Single Seat Fighter Project
Competitor to the Gloster Meteor

Fighter, Projects

Supermarine Type 327 “Spito” (Unicraft, Resin)

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TYPE: Fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two Rolls-Royce Merlin liquid-cooled engines, rated at 1,240 hp each

PERFORMANCE: 450 mph at 15.000 ft

COMMENT: The Supermarine Type 324 and Type 325 were British two-engined fighter designs proposed as the replacement for the Supermarine Spitfire and Hawker Hurrican. Neither of them nor a revised design – the Type 327 – to carry cannon was accepted for development and production.
As an aircraft to succeed the Hurricane and Spitfire then entering service, Air Ministry specification F.18/37 required a 400+ mph (at 15,000 ft) fighter with twelve .303 inch machine gun armament.
Hawker Aircraft submitted a single seat, single engine design with two possible engines, the Hawker Typhoon powered by the Rolls-Royce Vulture and the Hawker Typhoon, with Napier Sabre engine.
Gloster submitted two similar twin-boom designs with 12 Browning machine guns in the nose and a pusher Napier Sabre engine as well as an adaptation of their proposal to F.9/37 with nose-mounted armament.
Bristol’s design was one airframe offered with three alternative engines.
In 1938 Supermarine submitted brochures describing the Type 324 (under the company specification No.458) along with the Type 325. Both were compact twin-engine designs – one tractor and one pusher – with either Rolls-Royce Merlin or Bristol Taurus engines.
Hawker’s designs – which Sydney Camm had been working on since April 1937 – were accepted and prototypes of each ordered.
The Type 324 was a low-wing, twin-engined monoplane featuring the elliptical wing shape of the Spitfire, with retractable tricycle undercarriage.
Twin engines were expected to give a maximum speed of 450 mph. In addition, the twin layout gave the usual advantages of torque cancellation, improved pilot view, tricycle landing gear, performance, improved take-off performance and allowed the use of the proven Rolls-Royce Merlin engine.
The structure of the aircraft was Alclad aluminium alloy. The wing was designed in sections, so that alternative engines (Bristol Taurus) or armament could be accommodated. Fowler flaps were fitted for take-off/landing. Spoiler flaps were fitted to improve performance.
A number of armament types were considered. The main was 12 Browning in two packs of six in each wing outer section; these could be removed complete with ammunition to allow rapid rearming and servicing of the weapons.
When the Air Ministry felt progress on the Westland Whirlwind cannon-armed fighter was too slow, they asked for the F.18/37 tenders to be revised with 20mm cannon armament. Supermarine dropped the pusher design and proposed a six-cannon fighter as the Type 327 Spito. The Ministry did not feel its advantages outweighed other considerations, and that the Whirlwind – or the adaption oft he Bristol Beaufort – would enter service before Supermarine’s design could (Ref.: 24).

Cargo

Blohm & Voss FGP 227 (Anigrand, Resin)

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TYPE: Research Flying boat

ACCOMMODATION:  Crew of two

POWER PLANT: Six ILO F 12/400 air-cooled engines, rated at 21.1 hp each

PERFORMANCE: No data available

COMMENT: The FGP 227 was a scale flying model of the Blohm & Voss Bv 238 flying boat, built to provide data for the development of the Bv 238.
The proposed Blohm & Voss Bv 238 flying boat was to have an advanced hull design which had never been tried before. The Czech Flugtechnische Fertigungsgemeinschaft Prag (FGP) was engaged to build a quarter-scale test aircraft.
The FGP 227 was a faithful, approximately quarter-scale model of the proposed design, having a long, narrow hull with a high-mounted wing and conventional tail. The pilot sat in a front cockpit and the flight test observer in another one aft of the wing. Power was supplied by six 21 hp ILO F 12/400 air-cooled two-stroke engines driving three bladed propellers, mounted along the wings.The model was completed early in 1944, registered as BQ+UZ and fitted with a temporary wheeled undercarriage of ten small wheels fitted with low-pressure tyres.
Intended to allow flight tests to commence from the manufacturers airfield, the FGP 227 refused to take-off from the grass airfield. The aircraft was dismantled and transported to Erprobungsstelle See, Travemünde (E-Stelle – flying boat testing station). During transport French prisoners of war loading the wing onto flat-bed trucks allowed it to fall from a crane causing damage which was not repaired until September 1944.
Flight tests commenced in September 1944 as soon as the repairs were completed, but all six engines stopped due to fuel starvation soon after take-off, resulting in a heavy landing on the water. The FGP 227 was again repaired after which the aircraft flew several more times. By this time construction and testing of the Bv 238 had started, so no useful data was gleaned from the programme (Ref.:24).

 

 

Heavy Bomber, Reconnaissance, Cargo

Blohm & Voss Bv 238 V1, (Airmodel, Vacu)

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TYPE: Long-range Transport, Maritime Patrol and Bomber Flying Boat

ACCOMMODATION: Crew of 12

POWER PLANT: Six Daimler-Benz DB 603D liquid-cooled engines, rated at 1,900 hp each

PERFORMANCE: 264 mph at 60,000 kg at 20,000 ft

COMMENT: The Blohm & Voss BV 238 was a German flying boat, built during World War II. It was the heaviest aircraft ever built when it first flew in 1944, and was the largest aircraft produced by any of the Axis powers during World War II.
Development of the BV 238 giant flying boat began in 1941, following the success of the smaller but still enormous Blohm & Voss Bv 222 Wiking.
An approximately quarter-scale model of the Bv 238 was commissioned to test the new, long and slim hull design. Built by the Flugtechnische Fertigungsgemeinschaft GmbH in Prag (FGP), the FGP 227 arrived too late to contribute any data to the program.
Although extensive defensive armament was planned the first prototype, the Bv 238 V1, had none. It began flight trials in April 1944 but was strafed and partially sunk while moored on Lake Schaal, some miles to the east of Hamburg. One wing remained above water and it was salvaged, but by this time the war had ended and the Allies refused to let it be restored so it was taken out to deeper water and sunk.
The Bv 238 was an extremely large flying boat of conventional aerodynamic design, but bearing the usual B&V structural hallmarks of all-metal construction with a tubular steel wing main spar which also acted as the armoured main fuel tank. Of the era, only the earlier soviet Tupölev ANT-20, the americam Martin XPB2M-1 and the later Hughes H-4 Hercules had a bigger wing span. However it would be the heaviest yet flown, at 100 tonnes  fully loaded.
The hull had an unusually long and slim planing bottom, of essentially two-step design but with a row of smaller auxiliary steps behind the main one. A large nose door opened onto its cavernous interior, with the main crew cabin immediately above and behind it.
The wing was of straight, constant-chord form with tapered outer sections. Auxiliary floats were integrated into underside panels of the outer sections and could be retracted to lie flush with the wing. A catwalk ran internally along the wing in front of the tubular steel main spar, providing access to the engines in flight.
Power was provided by six 1,750 hp Daimler-Benz DB 603 liquid-cooled inverted V12 piston engines, arranged in nacelles along the leading edge of the centre section.
A landplane version, initially called the Bv 238-Land, was proposed, capable of carrying out transport, long-range bombing and transatlantic reconnaissance duties. The lower hull was replaced by a plain fairing with retractable undercarriage comprising twelve main and two nose wheels. One bomb bay filled the space between the wheel bays, another lay behind the main undercarriage. The wing floats were similarly replaced with retractable outrigger stabilising wheels. The nose wheel could be folded up, making the aircraft “kneel” and allowing vehicles to drive directly on- and off-board via a loading ramp to the nose doorway. Alternatively, passenger seating could be fitted. A further, upper deck behind the crew cockpit accommodated further passengers, bringing the total capacity to 300 troops.
Renamed the Blohm & Voss Bv 250 in 1942, three prototypes were ordered but none were finished by the end of the war (Ref.: 24).

 

Composite, Projects

Arado Ar 234C-2 (Dragon) with Focke-Wulf “Rammer” (Unicraft, Resin)

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Fighterbomber, Projects

Kawasaki Ki-119 (Unicraft, Resin)

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TYPE: Light bomber. Project

ACCOMMODATION: Pilot only

POWER PLANT: Mitsubishi Ha-104 radial engine, rated at 1,900 hp

PERFORMANCE: 360 mph at 19,685 ft

COMMENT: The Kawasaki Ki-119 was a design for a single-engine light bomber that would have been used in the defense of the Japanese homeland. Earlier Japanese bombers had been designed to operate over long distances, either in China or over the Pacific, but by the start of 1945 it was clear that the Japanese army might soon be fighting on home soil. This meant that a short range single-engine bomber would be possible, saving on the limited supply of both engines and trained air crew.
In March 1945 the Army Air Force issued Kawasaki with orders to produce a single seat bomber that could carry 1,764lb of bombs to targets 373 miles from its base, armed with two 20mm cannon and powered by one 1,900 hp Army Type 4 radial engine. Unlike many new aircraft being developed in Japan in 1945 the Ki-119 was not designed to be used in suicide attacks.
Takeo Doi and his team produced a design and a mock-up in three months. The fuselage was based on that of the Kawasaki Ki 100 radial-engine fighter. The aircraft was made as easy to fly as possible – a wide track undercarriage with good shock absorbers was chose to make the aircraft easy to handle on the ground, and large wings with a high aspect-ratio were designed, to make it easy to handle in the air. The aircraft was designed to carry three different sets of armament. In its basic light bomber role it was to be armed with two 20mm cannon and one 1,764lb bomb. It could also serve as a fighter escort, with no bombers but two extra 20mm cannons, or as a dive bomber with two 551lb bombs.
The impressively rapid development of the Ki-119 came to a halt in June 1945 when the detailed drawings were destroyed when American air raids damaged Kawasaki’s factory at Kagamigahara. This pushed back the expected delivery date for the prototype from September until November, with production expected in time for the new aircraft to take part in the fighting of 1946. The unexpectedly sudden end to the war meant that the prototype was never completed (Ref.: 24).