All posts by Gunther Arnold

Arado Ar 234B-2 “Blitz” (“Lightning”), (9/KG 76), (Dragon)

TYPE: Fast medium bomber

ACCOMMODATION: Pilot only

POWER PLANT: Two Junkers Jumo 004B-1 turbojet engines, rated at 900 kp each

PERFORMANCE: 461 mph at 20,000 ft

COMMENT: In late 1940, the Reichsluftfahrtministerium (RLM, Reich Air Ministry), offered a tender for a jet-powered high-speed reconnaissance aircraft with a range of 1,340 mi. Arado was the only company to respond, offering their E.370 project, a high-wing conventional-looking design with a Junkers Jumo 004 tubojet engine under each wing.
Arado estimated a maximum speed of 480 mph at 20,000 ft, an operating altitude of 36,000 ft and a range of 1,240 mi. The range was short of the RLM request, but they liked the design and ordered two prototypes as the Arado Ar 234. These were largely complete before the end of 1941, but the Jumo 004 engines were not ready, and would not be ready until February 1943. When they did arrive they were considered unreliable by Junkers for in-flight use and were cleared for static and taxi tests only. Flight-qualified engines were finally delivered, and the first prototype, the Ar 234 V1 made its first flight on July 1943 at Rheine Airfield.
By September 1943, four prototypes were flying and four more prototypes under construction. The sixth and eighth aircraft of the series were powered with four BMW 003 turbojet engines instead of two Jumo 004s, the sixth having four engines housed in individual nacelles and the eighth flown with two pairs of BMW 003s installed within “twinned” nacelles underneath either wing. These were the first four-engine jet aircraft to fly.
The projected weight for the aircraft was approximately 8 tonnes. To reduce the weight of the aircraft and maximize the internal fuel the eight prototype aircraft were fitted with the original arrangement of trolley-and-skid landing gear, intended for the planned operational, but never-produced Arado Ar 234A version.
Arado did not use the typical retractable landing gear. Instead, the aircraft was to take off from a jettisonable three-wheeled, tricycle gear-style trolley and land on three retractable skids, one under the central section of the fuselage, and one under each engine nacelle.
The RLM had already seen the promise of the design and in July 1943 had asked Arado to supply two prototypes of a “Schnellbomber” (“Fast bomber”) version as the Arado Ar 234B. Since the original skid-equipped Ar 234A’s fuselage design was very slender and filled with fuel tanks, there was no room for an internal bomb bay and the bombload had to be carried on external racks.
Since the cockpit was directly in front of the fuselage, the pilot had no direct view to the rear, so the guns were aimed through a periscope, derived from the type used on German World War II tanks, mounted on the cockpit roof. The Ar 234B version was modified to have fully retractable tricycle landing gear, with the mid-fuselage very slightly widened to accommodate the forward-retracting main gear units, the nose gear retracting rearwards. The first twin-Jumo 004 powered prototype Ar 234B (V 7) flew on 10 March 1944 for the first time and made history on 2 August 1944 as the first jet aircraft ever to fly a reconnaissance mission.
Production B-series aircraft  were slightly wider at mid-fuselage to house the main landing gear, with a central fuel tank present (the middle one of a trio of fuel tanks) in the mid-fuselage location forward tank, central and an aft. Under tests with maximum bombload consisting of three SC 500 bomb, the Ar 234 V9 aircraft could reach 418 mph at 16,000 ft. This was still better than any bomber the Luftwaffe had at the time, and made it the only bomber with any hope of surviving the massive Allied air forces. The normal bombload consisted of two 500 kg bombs suspended from the engines or one large 1,000 kg bomb semi-recessed in the underside of the fuselage with maximum bombload being 1,500 kg. In case the full bomb load was to be deployed on an Ar 234B for an operational sortie, fuel had to be reduced and two Walter HWK 109-500A-1 “Starthilfe” (Take-off assistance) liquid fuel jettisonable JATO rocket pods delivering 500kp thrust each were fixed under each wing.
Production lines were already being set up, and 20 Arado Ar 234B-0 pre-production aircraft were delivered by the end of June 1943. Later production was slow, as the Arado plants were given the simultaneous tasks of producing aircraft from other bombed-out factories hit during the USAAF’s “Big Week”, and the ongoing license-building and nascent phasing-out of Heinkel’s heavy He 177A bomber, even as the Arado firm was intended to be the sole subcontractor for the Heinkel He 177B (He 277) series strategic bomber, meant to start construction at Arado as early as October 1944. Meanwhile, several of the Ar 234 prototypes – including a few of the surviving six twin-engine Jumo 004-powered “trolley-and-skids” Ar 234A-series prototypes – were sent forward in the reconnaissance role. In most cases, it appears they were never even detected, cruising at about 460 mph at over 29,900 ft, with the seventh prototype achieving the first-ever wartime reconnaissance mission over the United Kingdom by a Luftwaffe-used jet aircraft.
The few 234Bs entered service in autumn and impressed their pilots. They were fairly fast and completely aerobatic. The long takeoff runs led to several accidents; a search for a solution led to improved training as well as the use of two jettisonable RATO units. The Jumo 004 engines were always the real problem; they suffered constant flameouts and required overhaul or replacement after about 10 hours of operation.
The most notable use of the Arado Ar 234 in the bomber role was the attempt to destroy the Ludendorff Bridge at Remagen. The aircraft continued to fight in a scattered fashion until Germany surrendered on 8 May 1945. Some were shot down in air combat, destroyed by flak, or “bounced” by Allied fighters during takeoff or on the landing approach, as was already happening to Messerschmitt Me 262 jet fighters. Mostly the remaining aircraft sat on the airfields awaiting fuel that never arrived.
Overall from mid-1944 until the end of the war a total of 210 aircraft were built. In February 1945, production was switched to the Arado Ar 234C variant. It was hoped that by November 1945 production would reach 500 per month. Only a few of this four engine aircraft were built before Germany finally collapsed (Ref.: 24).

Messerschmitt Me 262 HG III/ Concept 3 (Unicraft Models, Resin)

TYPE: High-speed test aircraft. Project

ACCOMMODATION: Pilot only

POWER PLANT: Two Heinkel-Hirth HeS 011 turbojet engines, rated at 1,300 kp thrust each

PERFORMANCE: High subsonic speed, estimated

COMMENT: In early 1941 several high speed versions of the basic Messerschmitt Me 262 were designed on the drawing board. The first of these “Hochgeschwindigkeitsjäger” (HG), (High-speed fighter) was the Messerschmitt Me 262 V9, unofficially called HG I. This aircraft featured modified wing leading edges of the inner wing section, swept angles of stabilizers, and a “Rennkabine” (Racing canopy), shallow, low-drag cockpit canopy and windscreen with low profile.
Other two projects were created following this way: The Me 262 HG II called for an outboard wing of increased chord and an improved air intake and engine installation, and finally  the Me 262 HG III, which was the final stage of development. It required more radical modifications, as a new 45 degree swept wing with engines housed in the wing roots. Three variants of the Me 262 HG III are known correspond to the original layout.
Entwurf 1” (Concept 1) had a the original tail plane of the Me 262, “Entwurf 2” (Concept 2) had a butterfly-type tail plane, and “Entwurf 3” (Concept 3) together with various subtypes was considerably altered in the fuselage area, where the cockpit was relocated at the rear and formed a part of the empennage group. The swept back stabilizers were located behind the cockpit. This Messerschmitt Me 262 HG III/ Concept 3 attained a very high state of fighter technology, which in the post-war period was the only realized abroad after a passage of several years.

M6A1-K “Nanzan” (“South Mountain”), (‘Shisei-Seiran Kai), (MPM-Models)

TYPE: Trainer aircraft for Aichi M6A1 “Seiran”

ACCOMMODATION: Pilot and trainer

POWER PLANT: One Aichi Atsuta Type 32 liquid-cooled engine, rated at 1,400 hp

PERFORMANCE: 310 mph at 17,060 ft

COMMENT:  The Aichi M6A1-K “Seiran Kai” was a trainer version of the submarine-launched attack floatplane Aichi M6A1 “Seiran”. It was fitted with an inwardly-retracting undercarriage, and the folding tip of the rudder was dispensed with as the absence of floats improved directional stability. The popular name of the M6A1-K was later changed to “Nanzan” (Southern Mountain”).
Two prototypes of this aircraft were built and flight tested before the war in the Pacific ended in 1945 (Ref.: 24).

Consolidated B-24D “Liberator” “Striped Ass”, 466th BG (H), 8th USAAF, (Airfix Models)

TYPE: Heavy bomber, Assembly ship

ACCOMMODATION: Crew of four

POWER PLANT: Four Pratt & Whitney R-1830-43 Twin Wasp radial engines, rated at 1,200 hp each

PERFORMANCE: 303 mph at 25,000 ft

COMMENT: The Consolidated B-24 “Liberator was a heavy long-range bomber of the USAAF during WW II and large aircraft for its day. It had a wing span of 110 feet and a gross weight of more than 30 tons. Powered by four 1,200 hp radial engines, it had a maximum fuel capacity of 2,814 US gallons and the bomb load varied from 2,000 to 4,000 kp depending on the distance of the target to be attacked. The crew varied from eight to 10 men, five or six of whom acted as gunners, manning the 10 machine guns usually carried for defence.
The operating technique with these heavy bombers was, after take-off, to assemble large formations of from 20 to 40 aircraft while climbing to operational altitude of 20,000 to 25,000 feet. This was coordinated by means of “Assembly Ships” (or “Formation Ships”) specially fitted to aid assembly of individual group formations. They were equipped with signal lighting, provision for quantity discharge of pyrotechnics, and were painted with distinctive group-specific high-contrast patterns of stripes, checkers or polka dots to enable easy recognition by their flock of bombers. The aircraft used in most cases were veteran B-24Ds. All armament and armor was removed and arrangements for signal lighting varied from group to group, but generally consisted of white flashing lamps on both sides of the fuselage arranged to form the identification letter of the group. Such an assembly was despatched from a single airfield and joined with other formations to form a division column of perhaps 500 to 600 bombers.
The 446th Bombardment Group (H) with Component Squadrons 784th, 785th, 786th and 787th Bombardment Squadron (H) was activated on 1 Aug. 1943 at Alamogordo AAFd. NM. The training for combat commenced at Kearns Fd. Utah end Aug. 43, remaining there until Nov, 43, when the group moved back to Alamogordo AAFd, NM. In early Feb. 44 the group moved to Topeka AAFd, Kan and after a week’s stay began movement to the UK. Here the group was stationed at Attlebridge, Norfolk, for the last year of the war in Europe.
Combat aircraft were Consolidated B-24H, B-24J, B-24L and B-24M. In total the group flew 232 missions in the course of the year against strategic objectives like U-boat installations in Kiel, ball bearing works in Berlin, aircraft factories in Munich and oil refineries in Hamburg. Remarkably, the 785th Bomb Squadron flew 55 consecutive missions without loss. The aircraft shown here is the assembly ship of the 446th Bombardment Group. It’s a veteran Consolidated B-24D named “Striped Ass” (Ref: 2).

Notice: Identification markings of this aircraft are mostly hand-made. After airbrushing the surface with different aluminum-silver shading red stripes are applied according to the original. For this I used microthin precision slit tape, Bishop Graphics. Inc., Westlake Village, Ca. This is self-adhesive, in red color, extreme thin and easy to apply. Unfortunately transparent it needed to be painted stripe by stripe before being applied.

Messerschmitt Me P. 1110/II “Tunnel-Einlauf”, (“Tunnel-air-intake”) with Kramer X-4, (Planet Models, Resin)

TYPE: High altitude fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Heinkel-Hirth HeS 011 turbojet engine, rated at 1,300 kp

PERFORMANCE: 630 mph

COMMENT: In Autumn 1944, in the context of the “Jägernotprogramm” (“Emergency Fighter Program”) the Oberkommando der Luftwaffe (OKL, Luftwaffe High Command) requested for proposals for a new generation of fighter/interceptor aircraft in order to replace the Heinkel He 162 “Salamander” or “Volksjäger” (“Peoples fighter”).
Besides designs such as Blohm & Voss Bv P.212, Focke-Wulf Ta 183, Heinkel He P. 1078, and Junkers EF 128 Messerschmitt proposed its project Me P. 1110 with three different variants.
First of the designs was the Messerschmitt Me P.1110/I, a turbo-jet powered interceptor with a conventional-looking design with the air intakes located in the middle part of fuselage sides above the wing the inlet not protruding the cross section (“Rampen-Einlauf”, “Ramp-air-intake”). The wing was of wooden construction and was swept back to 60 degree at the wing root and 40 degree at the leading edge. The tail plane was conventional with elevators and a vertical fin and swept back. Power was provided by a Heinkel/Hirth HeS 011 turbojet engine. A pressurized cockpit with streamlined fairing,  tricycle landing gear and three MK 108 30mm cannon in the nose with a provision for two more in the wing roots was envisaged.
The second design was the Messerschmitt Me P.1110/II that differed from the Me P.1110/I mainly in a V-tail unit and a divided annular air intake behind the cockpit. The advantage of this unusual arrangement was that it would reduce drag by fifteen percent compared to a single nose air intake at the cost of four percent air flow reduction to the jet engines. To increase the air flow a supercharger was provided that additionally withdraw the boundary layer.
Like the Me P.1110/I, the Me P.1110/II had 40 degree swept-back wings, an HeS 011 jet engine and was armed with three MK 108 30mm cannon in the nose with a provision for two more in the wing roots.
The third design the Messerschmitt Me P.1110 “Ente” was of canard configuration with small wings in the front and larger wings in the rear part of the fuselage.
All projects would be soon dropped in favor of the Junkers EF 128 and none of the Messerschmitt designs made it to the prototype stage. (Ref.: 20, 22).

Bristol “Buckingham” B 1 (Valom)

TYPE: Medium bomber

ACCOMMODATION: Crew of two

POWER PLANT: Two Bristol “Centaurus” IX radial engines, rated at 2,520 hp each

PERFORMANCE: 336 mph at 12,000 ft

COMMENT : In early 1939 Bristol suggested a bomber variant of the “Beaufighter” with their Bristol “Hercules” engines. British policy at the time was an expectation for medium bombers to be provided from the US allowing British industry to concentrate on heavy bomber designs but a design was requested preferably based on an existing design which meant working with the Bristol “Beaufort” or “Beaufighter”.
Air Ministry specification B.7/40 called for a medium bomber to replace the Bristol “Blenheim”. The specification stipulated a speed of at least 300 mph at 5,000 ft, a normal load of 500 kg of bombs and a center turret armed with at least two 12.7 mm machine guns. Only Armstrong Whitworth Company tendered a full design but it did not meet with approval. So when Bristol brought their Type 162 (tentatively named “Beaumont”), which was fortunately well matched to B.7/40 specification, to the Air Staff, this led to a request to complete a mockup in 1940 and then a confirmed contract for three prototypes in February 1941. The “Beaumont” was based on the rear fuselage and tail of a “Beaufighter”, with a new center and front fuselage. The armament was a mid-upper turret with four machine guns, four more machine guns firing forward and two firing to the rear.
Construction began in late 1940, with a new Air Ministry Specification B.2/41 to be written around it. Changes in the requirements, removing dive bombing and ground attack support which incoming US bombers were expected to be capable of and increasing the performance to allow for the future, meant the “Beaumont” would no longer suffice. The changes in performance, requiring a bomb load of 4,000 lb, a speed of 360 mph and a range of 1,600 miles meant a redesign by Bristol to use the Bristol “Centaurus” engine.
The Bristol redesign with a larger wing and the more powerful engines was the Bristol ”Buckingham”. It had gun installations in the nose, dorsal and ventral turrets. Generally conventional in appearance, one unusual feature was that the bomb-aimer/navigator was housed in a mid-fuselage ventral gondola, resembling those on the earlier German Heinkel He 111H and American Boeing B-17C and -D in appearance. This was part of an attempt to give all the crew positions unobstructed views and access to each other’s positions. The bomb bay could hold up to 2,000 kg bombs. The rear of the gondola had a hydraulically powered turret with two Browning machine guns. The Bristol-designed dorsal turret carried four Brownings. A further four fixed, forward-firing Brownings were controlled by the pilot. Following more changes, specification B.2/41 was replaced by B.P/41. An order for 400, at an initial rate of 25 per month, was made with deliveries expected in March 1943. The first flight took place on 4 February 1943. During testing, the “Buckingham” exhibited poor stability which led to the enlargement of the twin fins, along with other modifications. The Bristol “Buckingham B1” was first flown 12 February 1944 with “Centarus” VI or XI engines, 400 ordered but reduced first to 300 then to 119, with only 54 built as bombers. Overtaken by events, it was mainly used primarily for transport and liaison duties (Ref.: 24).

Arado Ar. 340 (Anigrand Models, Resin)

TYPE: Medium bomber

ACCOMMODATION: Crew of four

POWER PLANT: Two Junkers Jumo 222 or Daimler-Benz DB 604 (both liquid-cooled) or BMW 802 (radial) piston engines
PERFORMANCE: 360 mph

COMMENT: In 1939, the “Technisches Amt des Reichluftfahrtministeriums” (RLM); (Technical Office of the Reich Air Ministry) issued specification for a “Bomber B” requirement.
The Reich Air Ministry ordered the aircraft to replace the Junkers Ju 88 and Dornier Do 217 bombers by 1943. At first four manufacturers submitted plans to the Air Ministry: Arado project E.340, Dornier Do 317, Focke-Wulf Fw 191, and Junkers Ju 288. Later, Henschel was asked to submit its Henschel Hs 130 design due to the expertise of this company with its experiments with pressurized cockpits. Meanwhile, Project “Bomber B” contest winner was the Arado design, officially named Ar 340.
While the designs of all other contenders were of more conventional layout the Arado Ar 340 was designed with a central fuselage containing all four crew members. The cockpit and rear compartment were glazed and pressurized. The projected Junkers Jumo 222 engines were positioned in a unique twin-boom arrangement connected only through the wing assembly, a configuration which offered the crew better visibility. The landing gear was mounted to the load-bearing wing center-section. The tail of the aircraft was a unique design, where the tail plane did not connect the two booms but was cantilevered outwards instead, each similar to the asymmetric Blohm & Voss Bv 141B booms and tail arrangement. Also similarly, this would have provided the rear gunner with a clear range of fire directly behind. The fuselage extended forwards beyond the engines, with the gunners situated behind the cockpit, ahead of the bomb bay and wing spars. The MG 151 cannon in the tail of the central fuselage would have been controlled with remote aiming through periscopes. There were also two remote-controlled “Fernbedienbare Drehlafette FDL 131” 13mm (remotely-controlled gun turrets) to be placed above and below the fuselage.
The Ar 340 was one of the steadily growing numbers of later-war military airframe designs designed to use the troublesome Junkers Jumo 222 engine. Otherwise an innovative design, these powerful engines were selected because they would have allowed the Arado Ar 340 to carry the required payload of 5,900 kg within a relatively compact airframe, despite their still-strictly developmental nature. As the development of the Junkers Jumo 222 engines were cancelled, plans were discussed to power the Arado Ar 340 with Daimler-Benz DB 605 liquid-cooled engines or BMW 802 radial engines. Meanwhile the RLM favoured the Junkers Ju 288 and the Arado project was not pursued.
Ultimately, the entire “Bomber B project” was cancelled, primarily as a result of the failure to develop the required engines (Ref.: 24).

Mitsubishi A7M2 “Reppū” (“Strong Gale”, “Sam”), (MPM Models)

TYPE: Carrier-borne and land-based fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Mitsubishi Ha-43 radial engine, rated at 2,200 hp

PERFORMANCE: 390 mph at 21,660 ft

COMMENT: Towards the end of 1940, the Imperial Japanese Navy asked Mitsubishi to start design on a 16-Shi carrier-based fighter, which would be the successor to the carrier-based Mitsubishi A6M “Rei-sen” (“Zeke”, Allied reporting code “Zero”). At that time, however, there were no viable high-output, compact engines to use for a new fighter. In addition, Mitsubishi’s design’s team was preoccupied with addressing early production issues with the A6M2b as well as starting development on the A6M3 and the 14-Shi interceptor which would later become the Mitsubishi J2M “Raiden” (Allied code “Jack”), a land-based interceptor built to counter high-altitude bombers). As a result, work on the “Rei-sen” successor was halted in January 1941.
In April 1942, the development of the A6M3 and the 14-Shi interceptor was complete, and the Japanese Navy once again tasked Mitsubishi with designing a new “Zero” successor to become the “Navy Experimental 17-Shi Ko (A) Type Carrier Fighter “Reppu” (“Strong Gale”, Allied reporting code “Sam”). In July 1942 the Navy issued specifications for the fighter: it had to fly faster than 397 mph above 20,000 ft, climb to 20,000 ft in less than 6 minutes, be armed with two 20 mm cannon and two 0.51 in machine guns, and retain the maneuverability of the A6M3 “Rei-sen”.
As before, one of the main hurdles was engine selection. To meet the specifications the engine would need to produce at least 2,000 hp, which narrowed choices down to Nakajima’s NK9 (Ha-45) under development (later becoming “Homare”), or Mitsubishi’s MK9 (Ha-43), which was also still being developed. Both engines were based on 14-cylinder Nakajima “Sakae” and Mitsubishi “Kinsei”, respectively) engines converted to 18-cylinder power plants. The early NK9 had less output but was already approved by the Navy for use on the Yokosuka P1Y “Ginga” (Allied code “Frances”), while the larger MK9 promised more horsepower.
With the larger, more powerful engine, wing loading became an issue. With the MK9 the engineers concluded it could fulfill the requirements; however, production of the MK9 was delayed compared to the NK9, and the Japanese Navy instructed Mitsubishi to use the NK9.
Work on the 17-Shi was further delayed by factories prioritizing Mitsubishi  A6M “Reisen” and Mitsubishi G4M (Allied code “Betty”) bomber production as well as further work on A6M variants and addressing Mitsubishi J2M “Raiden” issues. As a result, the 17-Shi, which became the A7M1, officially flew for the first time on 6 May 1944, four years after development started. The aircraft demonstrated excellent handling and maneuverability, but was underpowered as Mitsubishi engineers feared, and with a top speed similar to the A6M5 “Rei-sen”/”Zeke”. It was a disappointment, and the Navy ordered development to stop on 30 July 1944, but Mitsubishi obtained permission for development to continue using the Ha-43 engine, flying with the completed Ha-43 on 13 October 1944. The Mitsubishi A7M2 “Reppu” now achieved a top speed of 390 mph, while climb and other areas of performance surpassed the “Zero”, leading the Navy to change its mind and adopt the aircraft. The A7M2 “Reppu” was also equipped with automatic combat flaps, used earlier on the Kawanishi N1K-J “Shiden” (Allied code “George”), significantly improving maneuverability.
In June 1945, ace pilot Saburo Sakai was ordered to Nagoya to test the airplane. He declared it to be the fastest fighter he had ever seen, able to surpass anything on the air, Japanese or American. He claimed it could fly in circles, while ascending, around a Grumman F6F “Hellcat” or a North American P-51 “Mustang”, and that engineers stated it could fight at up to 39,370 ft.
When the war in the Pacific area ended a total of 10 Mitsubishi A7M “Reppu’s” were built including only one production aircraft A7M2 (Ref.: 24).

Convair XB-46 (Anigrand Models, Resin)

TYPE: High-speed medium bomber

ACCOMMODATION: Crew of three

POWER PLANT: Four Allison J35A-3 turbojet engines, rated at 1.815 kp each

PERFORMANCE: 439 mph at 15,000 ft

COMMENT: In 1944, the US War department was aware of aviation advances in Germany and issued a requirement for a range of designs for medium bombers weighing from 36,287 kg to more than 90,718 kg. Designs from this competition, sometimes named the “Class of ’45”, included the Convair XB-46, the Martin XB-48, and the North American XB-45 “Tornado”.
In the fall of 1945, Convair found it was competing with itself with its XB-46 turbojet bomber when the USAAF became interested in an unorthodox forward-swept wing turbojet attack design, the Convair XA-44 that the company had also been working on. With the end of WW II severely curtailing budgets, the company considered canceling the XB-46 in favor of the other project as there was insufficient funding for both. Company officials argued that it made more sense to allow them to complete the XB-46 prototype as a stripped-down testbed omitting armament and other equipment and for the USAAF to allow them to proceed with two XA-44 airframes in lieu of the other two XB-46s on contract. In June 1946, the USAAF agreed to the substitution but that project was ultimately cancelled in December 1946 before the prototypes were completed. The XB-46 would be completed with only the equipment necessary to prove its airworthiness and handling characteristics.
The Convair XB-46 was a graceful design and had a long streamlined oval torpedo-shaped fuselage, long narrow straight shoulder-mounted wings with four Chevrolet-built Allison J35-C3 axial-flow eleven stage turbojets of 1.730 kp static thrust paired in an integral nacelle under each wing. The fuselage turned out to be a problem, as it distorted under flight loads. The pilots sat in tandem in a pressurized fighter-style cockpit under a single Plexiglas teardrop canopy with the bombardier-navigator-radio operator in a transparent Plexiglas nose section.
The straight wing had an aspect ratio of 11.6, and was equipped with Fowler flaps which extended over 90 percent of the span, in four sections. The flaps extended via electrical actuators, and had very small ailerons. Each wing had five spoilers made of perforated magnesium alloy. The engine air intakes were flat oval inlets, with a duct curving downward in a flat “S” to the engines, which were mounted behind the leading edge of the wing. The unusual flight control system utilized a system of pneumatic piping to transmit the pilots control inputs and actuate various systems, rather than the more typical hydraulic, manual or electrical control lines and systems of most aircraft of the era.
Production versions were to be equipped with a pair of .50 caliber Browning M2 machine guns in a tail turret designed by Emerson Electric Company and provision was made for an APG-27 remote control optics and sighting system, but no weaponry was fitted into the prototype.. Likewise, production aircraft were intended to be built with the General Electric J47 engines with 2.345 kp static thrust rather than the J35s used on the prototype
The XB-46’s first flight occurred 2 April 1947 after a month of taxi testing, and lasted ninety minutes. The pilot praised its handling qualities. Basic flight testing took place for five months, and by September 1947 it was concluded after 127 hours aloft on 64 flights by both the Convair Company and USAAF test pilots. Stability and control were excellent but there were engineering problems with engine de-icing, the cabin air system, and vertical oscillations caused by harmonic resonance between the wing and spoilers. There was also concern regarding the ability of the three man crew to exit the aircraft in case of an emergency, since the exit plan relied on the pneumatic system to hold the main door open against the airstream.
The B-46 program was cancelled in August 1947, even before flight testing had been completed, because it was already obsolete. The North American B-45 “Tornado” already had production orders, and even it would be eclipsed by the Boeing B-47 “Stratojet’s” superior performance (Ref.: 24).

Dornier Do 335A-0 “Pfeil” (Arrow”), (Dragon Models)

TYPE: Heavy Fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two Daimler-Benz DB 603A liquid-cooled engines, rated at 1,725 hp each

PERFORMANCE: 475 mph

COMMENT: The Dornier Do 335 “Pfeil” (“Arrow”) was a WW II heavy fighter built by the Dornier Company. It’s performance was much better than any other twin-engine designs due to its unique push-pull configuration and the lower aerodynamic drag of the in-line alignment of the two engines. It was Luftwaffe’s fastest piston-engine aircraft of World War II. The Luftwaffe was desperate to get the design into operational use, but delays in engine deliveries meant that only a handful were delivered before the war ended.
The origins of the Dornier Do 335 trace back to WW I when Claude Dornier designed a number of flying boats featuring remotely driven propellers and later, due to problems with the drive shafts, tandem engines. Tandem engines were used on most of the multi-engine Dornier flying boats that followed, including the highly successful Dornier Do J “Wal” (“Whale”) and the gigantic Donier Do X. The remote propeller drive, intended to eliminate parasitic drag from the engine entirely, was tried in the innovative but unsuccessful Dornier Do 14, and elongated, tubular drive shafts as later used in the Do 335 saw use in the rear engines of the four-engine, twinned tandem-layout Dornier Do 26 flying boat.
There are many advantages to this design over the more traditional system of placing one engine on each wing, the most important being power from two engines with the frontal area (and thus drag) of a single-engine design, allowing for higher performance. It also keeps the weight of the twin power plants near, or on, the aircraft centerline, increasing the roll rate compared to a traditional twin. In addition, a single engine failure does not lead to asymmetric thrust, and in normal flight there is no net torque, so the plane is easy to handle. The choice of a full “four-surface” set of cruciformly tail surfaces in the Do 335’s rear fuselage design, included a ventral vertical fin-rudder assembly to project downwards from the extreme rear of the fuselage, in order to protect the rear propeller from an accidental ground strike on takeoff. The presence of the rear pusher propeller also mandated the provision for an ejection seat for safe escape from a damaged aircraft, and designing the rear propeller and dorsal fin mounts to use explosive bolts to jettison them before an ejection was attempted — as well as twin canopy jettison levers, one per side located to either side of the forward cockpit interior just below the sills of the five-panel windscreen’s sides, to jettison the canopy from atop the cockpit before ejection.
In 1939, Dornier was busy working on the P.59 high-speed bomber project, which featured the tandem engine layout. In 1940, he commissioned a flying test bed, closely modeled on the airframe of the early versions of the twin engine Dornier Do 17 bomber but only 40% of the size of the larger bomber, with no aerodynamic bodies of any sort on the wing panels and fitted with a retractable tricycle landing gear to validate his concept for turning the rear pusher propeller with an engine located far away from it and using a long tubular driveshaft. This aircraft, the Göppingen Gö 9, built by , Schrempp-Hirth, a small sailplane company, showed no unforeseen difficulties with this arrangement, but work on the Dornier P.59 was stopped in early 1940 when the RLM ordered the cancellation of all projects that would not be completed within a year or so.
In May 1942, Dornier submitted an updated version his design as the Dornier P.231, in response to a requirement for a single seat, “Schnellbomber” -like high-speed bomber/intruder. P.231 was selected as the winner after beating rival designs from Arado, Blohm & Voss and Junkers, development contract was awarded as the Dornier Do 335. In autumn 1942, Dornier was told that the Do 335 was no longer required as a “Schnellbomber”, and instead a multi-role fighter based on the same general layout would be accepted. This delayed the prototype delivery as it was modified for the new role.
The Dornier Do 335 V1 first prototype flew in October 1943 and initial trials revealed essentially good handling characteristics. Acceleration was particularly favourable and the turning circle was rather better than had been anticipated. The use of a nose-mount annular radiator for the forward engine (much like a Junkers Jumo 211-powered Junkers Ju 88, or Jumo 213-powered Focke-Wulf Fw 190D-9) and a ventral-fuselage mount air-scooped radiator installation for cooling the rear engine (appearing like that on a North American P-51 “Mustang”) was distinctive.
However, several problems during the initial flight of the Do 335 would continue to plague the aircraft through most of its short history. Issues were found with the weak landing gear and with the main gear’s wheel well doors, resulting in them being removed for the remainder of the V1’s test flights. The Do 335 V1 made 27 flights, flown by three different pilots.
During these test flights the second Do 335 V2 was completed and made its first flight on December 1943, followed by the third Do 335 V3 on January 1944. In mid January 1944, RLM ordered five more prototypes, one to be built as Do 335A-6 night fighter. By this time, more than 60 hours of flight time had been put on the Do 335 and reports showed it to be good handling characteristics, but more importantly, it was a very fast aircraft. Even with one engine out, it reached about 350 mph.
Thus the Do 335 was scheduled to begin mass construction, with the initial order of 120 preproduction aircraft to be manufactured by DWF (Dornier-Werke Friedrichshafen) to be completed no later than March 1946. This number included a number of bombers, destroyers (heavy fighters), and several yet to be developed variants. At the same time, DWM (Dornier-Werke München) was scheduled to build over 2000 Do 335s in various models, due for delivery in March 1946 as well.
On 23 May 1944, as part of the developing “Jägernotprogramm” (“Emergency Fighter Program”) directive, maximum priority was given to Do 335 production. Furthermore, the decision was made, along with the rapid shut-down of many other military aircraft development programs, to cancel the Heinkel He 219 night fighter, which also used the DB 603 engines, and use its production facilities for the Do 335 as well. However, Ernst Heinkel managed to delay, and eventually ignore, its implementation, continuing to produce examples of the He 219A.
At least 16 prototype Do 335s were known to have flown as well as Muster-series prototypes on a number of DB603 engine subtypes. The first preproduction Do 335A-0s were delivered in July 1944 to the “Erprobungskommando 335” (“Proving detachment 335”) formed for service evaluation purposes. Approximately 22 preproduction aircraft were thought to have been completed and flown before the end of WW II including approximately 11 Do 335A-1 single-seat fighters of which two examples had been converted to a trainer version Do 335A-12 for training purposes (Ref.: 7., 24).