All posts by Gunther Arnold

Messerschmitt Me 209 V4 (Huma Models)

TYPE: Interceptor, fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Daimler-Benz DB 601A liquid-cooled engine, rated at 1,175 hp

PERFORMANCE: 370 mph app.

COMMENT: The designation Messerschmitt Me 209 was used for two separate projects during World War II. The first was a record-setting, single-engine race aircraft, for which little or no consideration was given to adaptation for combat (Messerschmitt Me 209 V1). The second Me 209 was a proposal for a follow-up to the highly successful Messerschmitt Bf 109 which served as the Luftwaffe’s primary fighter throughout World War II.
In late 1939, after three prototypes of the record-breaking aircraft were built the fourth prototype, the Messerschmitt Me 209 V4, was adapted to a fighter aircraft. The fuselage was essentially similar to that of the record-speed aircraft but the vertical tail surfaces were substantially increased in area, the main undercarriage legs were shortened, an entirely new wing was fitted, and the maximum gross weight was reduced.
For initial flight trials, the Me 209 V4 was fitted with a standard Daimler-Benz DB 601A engine and retained the surface evaporation cooling system employed by its  high-speed predecessors, but this system was far from perfection and continuously troublesome, and after the eighth test flight was removed  and replaced by shallow, low drag radiators beneath the inboard wing panels. The resumption of flying trials immediately revealed inadequacy of the cooling provided by the underwing radiators, and the handling characteristics of both on the ground and in the air proved extremely poor. By 1940, the overall wing span had been increased and both horizontal and vertical tail surfaces had been enlarged, but trial revealed no major improvement of the characteristics of the fighter.
With each successive modification weight escalated and performance diminished, and as the Me 209 V4 was by now decidedly underpowered, the DB 601A was replaced by a DB 601N affording 1,200 hp for take-off. But troubles still continued and further tests proved that speed performance was marginally lower than that of the standard Messerschmitt Me 109E. Finally all further development was abandoned.
However, combat actions with British Supermarine “Spitfires” showed an urgent need for a successor of the Luftwaffe’s Messerschmitt Me 109. So the Messerschmitt design bureau had been engaged in developing a modernized, more powerful derivative of the Me 109 and the RLM transferred the designation Me 209 to the new fighter which should employ a large portion of a standard Me 109 components. In fact, at the outset it was envisaged that there would be approximately 65 per cent airframe communality between the Me 109G and what now referred to as Messerschmitt Me 209-II (Ref.: 7).

 

Kugisho NK-1B (Unicraft, Resin)

TYPE: Interceptor, fighter. Project

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima NK-1B “Sakae” radial engine, rated at 1,100 hp

PERFORMANCE: No data available

COMMENT: On 26 April 1939, a German Messerschmitt Me 209 V1 set a new world speed record of almost 469 mph. This relative small Me 209 was a completely new aircraft and not to mistake for a replacement of the Messerschmitt Me 109, entering service with the Luftwaffe at the same time. Its only purpose was to set a new speed record.
Impressed by that speed the Imperial Japanese Navy Air Force authorized the Yokosuka Naval Air Technical Arsenal, Yokosuka also known as Kaigun Koku Gijutsusho or Kugisho to propose several designs of similar aircraft. In a complete reversal from previous Japanese Navy requirements priority was given speed, rate of climb, and maneuverability.
One design was built around a Nakajima NK1 “Sakae” radial engine, one of the most powerful engines available in Japan at that time. Another design proposed by Kugisho was the Kugisho HA-40, powered by a Kawasaki Ha-40 liquid-cooled engine derived from the German Daimler-Benz DB 601A. A more powerful variant of this engine was installed in the world record-breaking Messerschmitt Me 209 V1.
Although calculations and designs were in an advanced stage none of the Kugisho projects were realized
Noteworthy is the fact that the Imperial Japanese Army Air Force had similar projects, e. g. the Kawasaki Ki-60.

Douglas A-26B „Invader“ (Airfix)

TYPE: Light bomber, ground-attack aircraft

ACCOMMODATION: Crew of three

POWER PLANT: Two Pratt & Whitney R-2800-27 “Double Wasp” radial engines, rated at 2,000 hp each

PERFORMANCE: 355 mph


COMMENT
: The A-26 “Invader” was Douglas Aircraft’s successor to the A-20 (DB-7) “Havoc”, also known as Douglas “Boston”, one of the most successful and widely operated types flown by Allied air forces in World War II. The Douglas XA-26 prototype first flew on 10 July 1942. Flight tests revealed excellent performance and handling, but problems with engine cooling led to cowling changes and elimination of the propeller spinners on production aircraft. Repeated collapses during testing led to strengthening of the nose landing gear.
The Douglas A-26 was originally built in two different configurations. The Douglas A-26B had a gun nose, which originally could be equipped with a combination of armament including 12.7 mm machine guns, 20mm or 37mm auto cannon, or even a 75mm pack howitzer (which was never used operationally). Normally the gun nose version housed six (or later eight) .50 caliber machine guns, officially termed the “all-purpose nose”, later commonly known as the “six-gun nose” or “eight-gun nose”. The Douglas A-26C “Invader” had a glass” nose, officially termed the “Bombardier nose” and contained a Norden bombsight for medium altitude precision bombing.
After about 1,570 production aircraft, three guns were installed in each wing, coinciding with the introduction of the “eight-gun nose” for A-26Bs, giving some configurations as many as 14 12.7 mm machine guns in a fixed forward mount. A-26C nose section could be exchanged for an A-26B nose section, or vice versa, in a few man-hours, thus physically and officially changing the designation and operational role. The “flat-topped” canopy was changed in late 1944 after about 820 production aircraft, to a clamshell style with greatly improved visibility.
Alongside the pilot in an A-26B, a crew member typically served as navigator and gun loader for the pilot-operated nose guns. A tractor-style “jump seat” was located behind the “navigator’s seat”. In most missions, a third crew member in the rear gunner’s compartment operated the remotely controlled dorsal and ventral gun turrets, with access to and from the cockpit possible via the bomb bay but only when that was empty. The gunner operated both dorsal and ventral turrets via a novel and complex (and problematic) dual-ended periscope sight, which was a vertical column running through the center of the rear compartment, with traversing and elevating/depressing periscope sights on each end. The gunner sat on a seat facing rearward, and looked into a binocular periscope sight mounted on the column, controlling the guns with a pair of handles on either side of the column. When aiming above the centerline of the aircraft, the mirror in the center of the column would flip, showing the gunner what the upper periscope was seeing. When he pressed the handles downward, as the bead passed the centerline the mirror would automatically flip, transferring the sight “seamlessly” to the lower periscope. The guns would aim wherever the periscope was aimed, automatically transferring between upper and lower turrets as required, and computing for parallax and other factors. While novel and theoretically effective, a great deal of time and trouble was spent trying to get the system to work effectively, which delayed production, and it was difficult to keep maintained in the field even once production started.
The Douglas Company began delivering the production model A-26B to the USAAF on September 1943, with the new bomber first seeing action with the Fifth Air Force in the Southwest Pacific Theater on June 1944, when Japanese-held islands near Manokwari were attacked. The pilots in the 3rd Bomb Group’s 13th Squadron, “The Grim Reapers”, who received the first four A-26s for evaluation, found the view from the cockpit to be restricted by the engines and thus inadequate for low-level attack. General George Kenney, commander of the Far East Air Forces stated that, “We do not want the A-26 under any circumstances as a replacement for anything”.
Douglas needed better results from the “Invader’s” second combat test, so A-26s began arriving in Europe in late September 1944 for assignment to the Ninth Air Force. The initial deployment involved 18 aircraft and crews assigned to the 553rd Squadron of the 386th Bomb Group. This unit flew its first mission on September 1944. No aircraft were lost on the eight test missions, and the Ninth Air Force announced that it was happy to replace all of its Douglas A-20s and Martin B-26 “Marauders” with the Douglas A-26 “Invader” (Ref.: 24).

Junkers Ju 52/3mg14e (Italeri)

TYPE: Cargo and troop transport aircraft

ACCOMMODATION: Crew of two plus 18 troop

POWER PLANT:  Three BMW 132T-2 radial engines, rated at 830 hp each

PERFORMANCE: 168 mph at 2,000 ft

COMMENT: The Junkers Ju 52/3m (nicknamed “Tante Ju”, “Aunt Ju”) was German trimotor transport aircraft manufactured in Germany from 1931 until the end of WW II. In total 4.845 aircraft have been built.
Initially designed with a single engine but subsequently produced as a trimotor, Junkers Ju 53 /3m – suffix “3m” means “Drei Motoren” (three engines) it saw both civilian and military service from mid1930 onwards.
The Ju 52 was similar to the company’s previous Junkers W 33, although larger. Designed in 1930 at the Junkers works at Dessau, Germany, the aircraft’s featured an unusual corrugated duraluminium  metal skin, pioneered by Junkers during WW I, strengthened the whole structure.
The Ju 52 had a low cantilever wing, the midsection of which was built into the fuselage, forming its underside. It was formed around four pairs of circular cross-section duralumin spars with a corrugated surface that provided torsional stiffening. A narrow control surface, with its outer section functioning as the aileron, and the inner section functioning as a flap, ran along the whole trailing edge of each wing panel, well separated from it. The inner flap section lowered the stalling speed and the arrangement became known as the “Doppelflügel” ( “double wing”).
The outer sections of this operated differentially as ailerons, projecting slightly beyond the wingtips with control horns. The strutted horizontal stabilizer carried horn-balanced elevators which again projected and showed a significant gap between them and the stabilizer, which was adjustable in-flight. All stabilizer surfaces were corrugated.
The fuselage was of rectangular section with a domed decking, all covered with corrugated light alloy. There was a port side passenger door just aft of the wings, with windows stretching forward to the pilots’ cockpit. The main undercarriage was fixed and divided; some aircraft had wheel fairings, others not. There was a fixed tailskid, or a later tailwheel. Some aircraft were fitted with floats (Junkers Ju 52/3mg5e) or skis instead of the main wheels.
Originally powered by three Pratt & Whitney R-1690 “Hornet” radial engines, later production models mainly received 770 hp BW 132 engines, a license-built refinement of the Pratt & Whitney design. The two wing-mounted radial engines of the Ju 52/3m had half-chord cowlings and in planform view (from above/below) appeared to be splayed outwards, being mounted at an almost perpendicular angle to the tapered wing’s sweptback leading edge (in a similar fashion to the Mitsubishi G3M bomber (Allied code “Betty”) and Short “Sunderland” flying boat; the angled engines on the Ju 52 were intended to make it easier to maintain straight flight should an engine fail, while the others had different reasons). The three engines had either “Townend” ring or NACA cowlings to reduce drag from the engine cylinders, although a mixture of the two was most common, with deeper-chord NACA cowlings on the wing engines and a narrow “Townend” ring on the center engine, which was more difficult to fit a deeper NACA cowl onto, due to the widening fuselage behind the engine. Production Ju 52/3m aircraft flown by Luftwaffe usually used an air-start system to turn over their trio of radial engines, using a common compressed air supply that also operated the main wheels’ brakes.
In service with Lufthansa, the Junkers Ju 52/3m had proved to be an extremely reliable passenger airplane. Therefore, it was adopted by the Luftwaffe as a standard aircraft model and flew as a troop and cargo transport.. The Luftwaffe had 552 Ju 52/3ms in service at the beginning of WW II. Even though it was built in great and production continued until approximately the summer of 1944; when the war came to an end, there were still 100 to 200 aircraft available (Ref.: 24).

Kogiken Plan VIII High-Speed Reconnaissance Aircraft, (Unicraft Models, Resin)

TYPE: Fast reconnaissance aircraft, light bomber. Project

 

ACCOMMODATION: Crew of three

POWER PLANT: Four Mitsubishi Ha-211-II “Kinsai” (“Venus”) radial engines, rated at 1,075 hp each

PERFORMANCE: 481 mph (estimated)

COMMENT: In early 1941, Rikugun Kokugijutsu Kenkyujo (Japanese Army Aerotechnical Research Institute)  abbreviated “Kogiken”, formed a design group in order to study Japanese aviation technology in terms of what was possible at present and in the near future.
Of several high-speed reconnaissance aircraft concepts one of the designs was the Kogiken Plan VIII High Speed Reconnaissance aircraft. Including many concepts from Kogiken’s bomber design division, the Plan VIII aircraft was distinguished by its highly aerodynamic design. The cockpit for a crew of three was located at the tip of the fuselage, giving excellent view, and the glazing was flush with the rest of the airframe. Four Mitsubishi Ha-211-II radial engines were to be housed front-to-back in two stream-lined underwing engine nacelles, driving three-bladed tractor- and pusher propellers. Alternatively the Nakajima Ha-45 “Sakae” (“Prosperity”) radial engine, rated at 1,115 hp each could be installed. A tricycle landing gear was provided. The plane had a projected top speed of 481 mph and a maximum range of 1,864 miles. Due to its high speed no armament was provided. The design drawings were completed but although the calculated performance was promising the project was not realized (Ref: 24),

Fairey 0.21/44 (Unicraft Models, Resin)

TYPE: Carrier-borne torpedo-bomber, strike fighter. Project

ACCOMMODATION: Pilot and navigator

POWER PLANT: Two twin-coupled Rolls-Royce “Merlin” RM.14.SM, rated at 2,200 hp

PERFORMANCE: 360 mph at 15,000 ft

COMMENT: In autumn 1944 the Fairey Corporation was asked to assess the feasibility of adapting its original tandem, twin engine research studies to a new naval strike platform as a replacement of the troublesome Fairey “Spearfish”. The new aircraft was planned for use aboard the new 46,000 t “Malta”-class aircraft carriers then under development and as power units two tandem-coupled engines were proposed: The Rolls-Royce “Tandem Merlin” (Project A) or alternatively the Rolls-Royce “Twin Griffon” (Project B). Either design was intended to be a single-seat aircraft, although there was the possibility for adding a rear compartment for a navigator.
During March 1945, Fairey redesigned the “Project A’s” overall specifications. The plane would still employ the Rolls-Royce “Merlin” twin-coupled power plant, but the new version was streamlined and compacted. The aircraft was a cantilever, mid-wing monoplane, with an all-metal, monocoque fuselage, the centre wing section was built integral with the fuselage and the outer wing panels could be hydraulically folded for carrier operations. It had an internal weapons bay to hold a torpedo, retractable ASV Mk. XV surface search radar mounted behind the bomb bay, contra-rotating propellers, and a stronger outward retracting conventional landing gear with a tailwheel.  The cockpit was positioned high above the engine and offered an excellent view for the pilot, the navigators position was behind the cockpit in a separate copula operating a remote-controlled Frazer-Nash FN 95 barbette holding two 12,7 mm M2 Browning machine guns.
With the end of WW II and the upcoming turbojet- and turboprop-engines as well as the cancellation of all orders for new “Malta”-class aircraft carriers the Fairey design was abandoned. Nevertheless, in the post-war period this design influenced the development of the successful carrier-born anti-submarine aircraft Fairey “Gannet” (Ref.: Unicraft, 24).

Messerschmitt Me 262 HG III (Frank Airmodell, Resin)

TYPE: High-speed experimental aircraft. Project

ACCOMMODATION: Pilot only

POWER PLANT: Two Junkers Jumo 004D-1 turbojet engines, rated at 930 kp thrust each

PERFORMANCE: 683 mph at 19.685 ft

COMMENT: The final layout of the Messerschmitt Me 262 “Schwalbe” (“Swallow”) did not come up to all expectations of perfectionist Willy Messerschmitt. He argued that at least the concept of the new revolutionary aircraft is a result of many compromise and need to be improved. One goal is the high speed that can be reached by a turbojet driven aircraft.
Already in 1939 when the first design studies began what later became the Messerschmitt Me 262 Willy Messerschmitt proposed the installation of the turbojet engines into the wing roots in order to reduce drag and save weight. But at that time the plan failed due to the rapid changing dimensions of the first “Sondertriebwerke” (“Exceptional power plants”) as the new turbojet engines are called..
Yet another possibility to reduce drag in high-speed flight was the introduction of swept-back wings. In 1935 Prof. Busemann, an aeronautical research scientist at the aerodynamic institute of the University of Göttingen, discovered the benefits of the swept wing for aircraft at high speeds. He presented a paper on the topic at the Volta Conference at Rome in 1935. The paper concerned supersonic flow only. At the time of his proposal, flight much beyond 300 miles per hour had not been achieved and it was considered an academic curiosity. Nevertheless, he continued working with the concept, and by the end of the year had demonstrated similar benefits in the transonic region as well.
By early 1940 the first precise research findings on swept back wings were available to the German aircraft industry and Messerschmitt proposed in April 1941 to fit up the piston engine driven Messerschmitt Me 262 V1 with a 35 degree swept back wing. Nevertheless, at that time priority was given to the mass-production of the Messerschmitt Me 262 “Schwalbe” (“Swallow”). But with the introduction of this phenomenal aircraft the influence of critical Mach-number (“compressibility”) on subsonic speed became noticeable. In early 1944 research work on development of a high-speed variant of the Messerschmitt Me 262 was done again in three steps as so called “Hoch-Geschwindigkeitsjäger” , suffix “HG” (“High-speed fighter”):

Messerschmitt Me 262 HG I
The leading edge of the inner wing as well as of the vertical tail was increased to 45 degree, the leading edge of the horizontal tail was swept back to 40 degree, a shallow, low-drag cockpit canopy was installed, and the muzzles were faired over.

Messerschmitt Me 262 HG II
A new wing with 35 degree sweep was installed, the engine nacelle was improved, a shallow, low-drag canopy and a butterfly tail-plane was provided.

Messerschmitt Me 262 HG III
Improvements were a new 45 degree swept-back wing, installation of turbojet engines in wing-root, low-drag canopy and swept-back tail-plane.
The last variant was intensively discussed and tested especially the installation of more powerful turbojet engines (Heinkel-Hirth HeS 011). The end of WWII stopped all further work on the Messerschmitt Me 262 HG III (Ref.: 20, 24).

Mitsubishi Ki-202 “Shūsui-Kai” (“Sharp Sword”) (A + V Models, Resin)

TYPE: Interceptor aircraft. Project

ACCOMMODATION: Pilot only

POWER PLANT: One Mitsubishi Toku Ro.3 (KR20) liquid fuel rocket engine, rated at 2,000 kp thrust plus one additional rocket, rated at 750 kp thrust

PERFORMANCE: 559 mph at 32,808 ft

COMMENT: The Mitsubishi Ki-202 “Shūsui-Kai” (translated as “Sharp Sword, improved”) was a direct development of the Mitsubishi Ki-200 “Shusui” rocket-powered interceptor aircraft. None were produced before Japan’s surrender that ended WW II.
In a split from the development of the IJ Navy Mitsubishi J8M “Shusui” and Army’s Mitsubishi Ki-200 “Shusui”, the IJ Army instructed Rikugun Kokugijitsu Kenkyujo (Army Aerotechnical Research Institute) to develop a new design originally based  on the German Messerschmitt Me 163 “Komet” (“Comet”), built in Japan as a joint Navy-Army venture.
A fundamental shortcoming of the Messerschmitt Me 163, and all other aircraft based on it, was extremely limited endurance, typically only a few minutes. The Imperial Japanese Navy proposed to improve the endurance of the J8M1 by producing a version with only one cannon, thereby saving weight and space for more fuel, designated J8M2. The Imperial Japanese Army, on the other hand, opted to keep both cannon, but enlarge the airframe to accommodate larger tanks, resulting in the Mitsubishi Ki-202 “Shusui-Kai”, which was to have been the definitive Army version of the fighter. Power was to be supplied by a 2,000 kg thrust delivering Mitsubishi Toku Ro.3 (KR20) rocket motor. An additional rocket engine with reduced thrust was used for cruising speed. Undercarriage was to have been a sprung skid and tail-wheel.
Similar development was done in Germany. The Messerschmitt Me 163 variant Messerschmitt Me 163C had a lengthened fuselage to accommodate larger fuel tanks while the Messerschmitt Me 263 was a complete new design with increased flight endurance (Ref.: 24).

Curtiss SC-1 “Seahawk” (SMER Models)

TYPE: Scout seaplane

ACCOMMODATION: Pilot only

POWER PLANT: One Wright R-1820-62 “Cyclone” radial engine, rated at 1,350 hp

PERFORMANCE: 125 mph

COMMENT: The Curtiss SC “Seahawk” was a scout seaplane designed by the Curtiss Aeroplane and Motor Company for the US Navy. The existing Curtiss SO3C “Seamew” and the Vought OS2U “Kingfisher” were 1937 designs that, by 1942, needed to be replaced.
Work began in June 1942, following a US Navy Bureau of Aeronautics request for scout seaplane proposals. Curtiss submitted the “Seahawk” design on 1 August 1942, with a contract for two prototypes and five service test aircraft awarded on 25 August that year. A production order for 500 SC-1s followed in June 1943, prior to the first flight of the prototypes.
While only intended to seat the pilot, a bunk was provided in the aft fuselage for rescue or personnel transfer. Two 12.7 mm M2 Browning machine guns were fitted in the wings, and two underwing hardpoints allowed carriage of 113 kg bombs or, on the right wing, surface-scan radar. The main float, built by Edo Company was designed to incorporate a bomb bay. But this suffered substantial leaks when used in that fashion, and was modified to carry an auxiliary fuel tank.
The first flight of a prototype XSC-1 took place on February 1944. Flight testing continued through April, when the last of the seven pre-production aircraft took to the air. Nine further prototypes were later built, with a second seat and modified cockpit, designated SC-2; series production was not undertaken.
The first serial production “Seahawks” were delivered on October 1944, to the USS CB-2 “Guam”. All 577 aircraft eventually produced for the Navy were delivered on conventional landing gear and flown to the appropriate Naval Air Station, where floats were fitted for service as needed.
Capable of being fitted with either float or wheeled landing gear, the “Seahawk” was arguably America’s best floatplane scout of WW II. However, its protracted development time meant it entered service too late to see significant action in the war. It was not until June 1945, during the pre-invasion bombardment of Borneo, that the “Seahawk” was involved in military action. By the end of the war, seaplanes were becoming less desirable, with the “Seahawk” being replaced soon afterward by helicopters (Ref.: 24).

Focke-Wulf Projekt VII “Flitzer” (“Streaker“ or „Dasher)” (Revell)

TYPE: Interceptor fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Heinkel-Hirth HeS 011A turbojet engine, rated at 1,300 kp thrust plus one Walter HWK 509A-2 liquid-fuel rocket engine, rated between 300 and 1,500 kp thrust

PERFORMANCE: 593 mph (estimated)

COMMENT: In March 1943 the Focke-Wulf design team in Bremen initiated a series of studies for single-seat, single turbo jet powered fighters. “Entwurf 6”, also known as “Projekt VI”, was approved for mock-up construction in February 1944. The designation was later changed to “Projekt VII” and was given the code name “Flitzer (“Streaker” or “Dasher”). The design had mid-fuselage mounted wings with moderate sweepback (32 degrees), air inlets in the wing roots, twin booms, a high mounted tail plane and a tricycle landing gear. For high speed interception the single He S 011A turbojet was to be supplemented with a Walter HWK 509 A-2 bi-fuel rocket mounted below the turbojet engine. This arrangement was later revised and the rocket engine was eliminated. Projected armament consisted of two MK 103 30mm cannon or two MK 108 30mm cannon in the lower nose and two MG 151/20 20mm cannon in the wings. The Focke-Wulf Flitzer” was well advanced in development, a full-size mock-up and some prototype sub-assemblies being completed. The project was eventually abandoned in favor of the Focke-Wulf Ta 183 “Huckebein”. In the meantime this design was in an advanced stage for series production.

Noteworthy is the fact that the Focke-Wulf “Flitzer” project had great similarity with the contemporary British de Havilland DH 100 “Vampire” (Ref.: 17, 24).