All posts by Gunther Arnold

Bristol Blenheim Mk. V, RHAF, 13th Squadron (MPM Models)

TYPE: Light bomber

ACCOMMODATION: Crew of three

POWER PLANT: Two Bristol “Mercury” XXX radial engines, rated at 920 hp

PERFORMANCE: 266 mph at 11,800 ft

COMMENT: In 1940, a new specification, Spec B. 6/40, was issued by the U.K. Air Ministry to redesign the Bristol “Blenheim” Mk. IV. The major changes included the replacement of the “Mercury” XV engines with the uprated “Mercury” XXX engines, a re-designed nose area, extra armor and a new oxygen system. On February 1941, two prototypes were ready for flight at the Bristol factory. One prototype was a three-seat, high-altitude day bomber. This version had a semi-glazed, asymmetrical nose with a rear-facing blister housing two machine guns. The second prototype was a two-seater close-support aircraft, with solid nose containing four more Browning machine guns, initially known as Bristol “Bisley” (after shooting competitions held at Bisley). This latter variant was not required, probably due to the advent of the single-seater close-support fighters then under development such as the Hawker “Typhoon”. A major improvement of the “Blenheim” Mk. V over its earlier predecessors was the new Bristol B. X. upper gun turret, which was fitted with two machine guns. This turret was capable of high-speed traverse and continuous rotation in either direction. The day bomber type went into production and, by June 1943, a total of 940 aircraft had been produced for the RAF. Manufacture of the “Blenheim” Mk. V was undertaken by the firm of Rootes Security Ltd, at their “shadow” factory at Blythe Bridges, Staffordshire. Although the “Blenheim” Mk. V served in North Africa and the Far East until 1943, its lack of success resulted in many aircraft converted to dual-control and being used as trainers and target tugs  (Ref.: MPM).


Tokyo Koku Ki-107 (A + V Model, Resin)

TYPE: Monoplane trainer

ACCOMMODATION: Teacher and student pilot

POWER PLANT: One Hitachi Hatsukaze Ha-47 inline piston engine, rated at 110 hp


COMMENT: The Tokyo Koku Ki-107 was a  Japanese military training aircraft for the Imperial Japanese Army Air Force. The Ki-107 was a wooden-built low-wing two-seat monoplane with an open cockpit. Powered by a Hitachi Hatsukaze Ha-47 (Ha-11) inline piston engine it first flew in October 1943.The Japanese Army had ordered 450 as primary trainers as replacement for the Kokusai Ki-86 (a license built German Bücker Bü 131 that used the same Ha-47 engine), but production was held up by air raids and only 29 had been delivered by the end of the war (Ref.: 24).

Tachikawa SS-1 (FEresin, Resin)

TYPE: Pressurized research transport aircraft


POWER PLANT: Two Mitsubishi Ha-102 radial engines, rated at 1,080 hp each

PERFORMANCE: 295 mph at 19,030 ft

COMMENT: In 1938 the Lockheed Aircraft Corporation exported to Japan a total of thirty of their Model 14-38 twin-engined passenger transport. Twenty aircraft were delivered between March and July 1938 to Tachikawa Hikoki K.K. for eventual re-sale to Nihon Koko K.K. (Japan Air Transport Co Ltd) while a further ten aircraft were delivered direct to Nihon Koku K.K. between June and September 1938. Operated by the airline and its successor, Dai Nippon Koku, on its routes linking Japan to China, the aircraft was powered by a pair of 900 hp Wright R-1820-G3B radials. Being used throughout the war, these civilian aircraft received the Allied code name of TOBY.
Tachikawa, also having successfully negotiated a manufacturing licence with Lockheed, decided to submit to the Army a proposal covering Japanese production of a modified version. As the Army urgently required air transport to support their operations in China, this proposal was favourably received, and in 1939 Tachikawa were instructed to undertake the manufacture of this aircraft to carry military personal. Powered by two 900 hp Mitsubishi Ha-26-I radials and designated Army Type LO Transport, these aircraft were also built by Kawasaki. As the aircraft’s handling characteristics were found somewhat unsatisfactory by Army pilots, Kawasaki were instructed to redesign the aircraft, and eventually this led to the production of the Kawasaki Ki-56. Despite its shortcomings, the Army Type LO Transport, known as THELMA to Allied forces, was operated until the Japanese surrender.
In late 1940, Tachikawa undertook to produce an experimental aircraft specifically for pressurization experiments. To speed up work, the wings, rear fuselage section and tail surfaces of the Army Type LO Transport were retained, and a shorter pressurized forward and centre fuselage section was designed. Of cylindrical cross section, the new forward fuselage had no windscreen step, and other modifications included the replacement of the Type LO power plants with two 1,080 hp Mitsubishi Ha-102 radials. Designated Tachikawa SS-1, the aircraft was completed in May 1943 and during its brief trials proved valuable data on cabin pressurization (Ref.: 1).

Dornier Do 24T-1 (Revell)

TYPE: Maritime reconnaissance and transport flying boat


POWER PLANT: Three Bramo 323R-2 Fafnir radial engines, rated at 1,200 hp with water injection each

PERFORMANCE: 211 mph at 15,750 ft

COMMENT: The Dornier Do 24 is a 1930s German three-engine flying boat designed by the Dornier Flugzeugwerke for
maritime patrol and search rescue. According to Dornier records, some 12,000 people were rescued by Do 24s during its flying career. A total of 279 were built among several factories from 1937 to 1945.
The Dornier Do 24 was designed to meet a Royal Netherlands Navy requirement for a replacement of the Dornier Wals (Do 16) being used in the Dutch East Indies, with the Netherlands government signing a contract for six Dornier Do 24s on August 1936. Two more prototypes were built for the German navy to be evaluated against the Blohm & Voss Bv 138.
The Do 24 was an all-metal parasol monoplane with a broad-beamed hull and stabilising sponsons. Twin tails were mounted on the upswept rear of the hull, while three wing-mounted tractor configuration engines powered the aircraft. Fuel was carried in tanks in the sponsons and the wing centre section. Up to 1,200 kg of bombs could be carried under the aircraft’s wings, while defensive armament consisted of three gun turrets, one each in nose, dorsal and tail positions. In early aircraft the turrets were each fitted with a machine gun but later aircraft carried a 20 mm cannon in the dorsal turret.
The Do 24 V3, the first of the Dutch boats, took off from Lanke Constance on July 1937, with the second Dutch boat, Do 24 V4 following soon after.
The Netherlands was enthusiastic about the new flying boat and planned to purchase as many as 90. Of these, 30 were to be built by Dornier (with all but the first two prototypes assembled by Dornier’s Swiss subsidiary based at Altenheim. The remaining aircraft were to be built under licence in the Netherlands by Aviolanda at Papendrecht. Of these aircraft, all but one of the German and Swiss built aircraft and the first seven Aviolanda-built aircraft were to be Do 24K-1s, powered by the original Wright R-1820-F52 cyclone 9 engines, while the remaining aircraft were to be Do 24K-2s, with more powerful  1,100 hp Wright R-1820-G102 engines and more fuel.
Only 25 aircraft had been built on the Aviolanda assembly line before the German occupation. The Luftwaffe were interested in the completed and partially completed aircraft. The Dutch production line continued to produce aircraft under German control. 11 airframes were completed with Dutch-bought Wright Cyclone engines but later models used the BMW Bramo 323R-2. A further 159 Do 24s were built in the Netherlands during the occupation, most under the designation Do 24T-1.
Another production line for the Do 24 was established in the old CAMS factory at Sartrouville, France, during the German occupation. This line was operated by SNCAN and was able to produce another 48 Do 24s. After the liberation, this facility produced a further 40 Do 24s, which served with the French Navy until 1952.
Thirty-seven Dutch- and German-built Do 24s had been sent to the East Indies by the time of the German occupation of the Netherlands in June 1940. Until the outbreak of war, these aircraft would have flown the tri-color roundel. Later, to avoid confusion with British or French roundels, Dutch aircraft flew a black-bordered orange triangle insignia.
After the Japanese invasion of the Netherlands East Indies, six surviving Do 24s were transferred to the Royal Australian Air Force in February 1942. They served in the RAAF through most of 1944 as transports in New Guinea.
In 1944, 12 Dutch-built Do 24s were delivered to Spain with the understanding that they would assist downed airmen of both sides. After the war, a few French-built Do 24s also found their way to Spain. Spanish Do 24s were operational at least until 1967, and possibly later. In 1971, one of the last flying Spanish Do 24s was returned to the Dornier facility on Lake Constance for permanent display (Ref.:24).


Dornier Do 18G-1 (Matchbox)

TYPE: Patrol and reconnaissance flying boat


POWER PLANT: Two Junkers Jumo 205C-4 liquid-cooled diesel engines, rated at 605 hp each

PERFORMANCE: 155 mph at sea level

COMMENT: In 1934, the Dornier Flugzeugwerke started development of a new twin-engined flying boat to replace the Dornier Do J Wal (Whale) in both military (Do 16) and civil (Do JI and Do J II) roles. The resultant design, Do 18 retained the layout of the “Wal”, with a metal hull fitted with distinctive stabilizing sponsons, and powered by two engines above the wing in a push-pull layout, but was aerodynamically and hydrodynamically more efficient. It was planned to be powered by two of the new Junkers Jumo 205 diesel engines. Although heavy, these promised to give much lower fuel consumption than conventional petrol engines of similar power.
The Do 18G, 62 units built, was an improved version, powered by two 880 hp Jumo 205D engines, armed with a 13 mm MG machine gun in the bow, and a 20 mm MG 151 cannon in a power-operated dorsal turret.
In German Luftwaffe service, the Dornier Do 18G was obsolete by the outbreak of World War II, but – as the only military flying boat – 62 (58 serviceable) aircraft in five squadrons were in use mainly on North Sea reconnaissance missions. In 1940 some squadrons changed their base to Norway. The vulnerable and underpowered flying boat was soon relegated to training and the air/sea rescue role. In the middle of 1941, only one squadron was still operational on Do 18. The Blohm & Voss Bv 138 had superseded the Dornier Do 18G.
A Dornier Do 18G was the first German aircraft to be shot down by British aircraft during the war, when one of a formation of three was caught over the North Sea by nine Fleet Air Arm Blackburn “Skua” fighter bombers of 803 Naval Air Squadron flying from HMS “Ark Royal” on 26 September 1939 (Ref.: 24).

Dornier Do 16 „Militärwal“(“Military Whale”) (Huma)

TYPE: Reconnaissance, transport and training flying boat

ACCOMMODATION: Crew of two to four plus 8-10 passengers or equivalent freight

POWER PLANT: Two BMW VI liquid-cooled engines, rated at 700 hp each


COMMENT: The Dornier Do J “Wal” (“Whale”) was a twin-engine German flying boat of the 1920s designed by Dornier Flugzeugwerke. The Do J had a high-mounted strut-braced monoplane wing with two piston engines mounted in tandem in a central nacelle above the wing; one engine drove a tractor and the other drove a pusher propeller. The hull made use of Claudius Dornier’s patented sponsons on the hull’s sides.
The Do J made its maiden flight on November, 1922. The flight, as well as most production until 1932, took place in Italy because of the restrictions on aviation in Germany after World War I under the terms of Treaty of Versailles. Dornier began to produce the “Wal” in Germany in 1931; production went on until 1936. The Dornier J I and its  variant J II “Wal” were some of the most famous flying boats of the periods between the world wars.
A military version was the Dornier Do J II d and was in service with the German Luftwaffe as Dornier Do 16 “Militärwal” (“Military Whale”) according to the aircraft designation system of 1934 by the ReichsLuftsfahrtMinisterium (Reich Air Ministry, RLM). It was used as a reconnaissance and transport aircraft. A crew of two to four rode in an open cockpit close to the nose of the hull. There was one machine gun position in the bow in front of the cockpit and one or two amidships.  Some 30 Dornier Do 16 “Militärwal” being delivered for the Luftwaffe in 1935. Eventually these were replaced by the Dornier Do 18 and the “Militärwal” was relegated to training roles.

Note: In many publications the Dornier J II d “Military Whale” is cited as Dornier Do 15. So done on my website, too, (but now corrected). The proper designation is Dornier Do 16 (Ref. 24).

Consolidated B-32 “Dominator” (Anigrand, Resin)

TYPE: Heavy bomber


POWER PLANT: Four Wright R-3350-23A radial engines, rated at 2,200 hp each

PERFORMANCE: 357 mph at 30,000 ft

COMMENT: The Consolidated B-32 “Dominator” was a heavy bomber made for the USAAF  during WWII, and had the distinction of being the last Allied aircraft to be engaged in combat during World War II. It was developed in parallel with the Boeing B-29 “Superfortress” as a fallback design should the B-29 prove unsuccessful. The design on which Consolidated based its proposal was similar to the Consolidated B-24 “Liberator”. Like the B-24 it was originally designed with twin fins and a large Davis-type wing, but with a longer, rounder fuselage and a rounded nose. The aircraft was designed to be pressurized, and have remote-controlled retractable gun turrets with fourteen .50 in machine guns. The turrets were remotely controlled from periscopic sights in aiming stations inside the aircraft. The sights were coordinated by a sophisticated analog computer system. The inboard propellers’ pitch could be reversed to shorten the landing roll or to roll back in ground maneuvers. The first prototype made its maiden flight on 7 September 1942. In 1943, the initial contract was signed for 300 B-32 but development problems continued. In order to resolve stability problems a B-29 style tail was fitted to the aircraft after its 25th flight. But this did not resolve the problem and a Consolidated-designed 19.5 ft vertical tail was added and first flown on the third XB-32 on 3 November 1943. By 1944 testing of the three prototypes permitted the USAAF to place orders for over 1,500 B-32s. The first production aircraft was delivered on 19 September 1944, by which time the B-29 was in full combat in the Pacific Area of Action. Beginning on 27 January 1945, 40 B-32A-5, -10 and -15 aircraft were delivered as unarmed TB-32-CF crew trainers. The B-32 only reached units in the Pacific Area during mid-1945, and subsequently only saw limited combat operations against Japanese homeland  before the end of the war. Most of the extant orders of the B-32 were cancelled shortly thereafter and only 118 B-32 airframes of all types were built (Ref.: 23).

Dornier Do 26D-0 (Airmodel, Vacu)

TYPE: Transport and reconnaissance flying boat


POWER PLANT:  Four Junkers Jumo 205D liquid-cooled, opposed-piston diesel engine, rated at 880 hp each


COMMENT: The elegant Dornier Do 26, sometimes referred to as the “most beautiful flying-boat ever built”, was of all-metal construction. Originally designed as a civilian transport aircraft for the “Deutsche Lufthansa”, the few aircraft built before  and immediately at the beginning of WW II were pressed into military service at the outbreak of the war in Europe.
The hull had a central keel and a defined step; the wings were of gull wing configuration, the outer sections being equipped with fully retractable narrow stabilizing wing-floats, instead of Dornier’s famous “water-wing” sponsons extending from the lower hull for lateral stabilization.
Its four Junkers Jumo 205 diesel engine, were mounted in tractor/pusher pairs in tandem nacelles located at the joint between the dihedral and horizontal wing sections. The rear (pusher) engines could be swung upwards through 10° during take-off and landing, to prevent contact between the three-blade airscrew and water spray created by the forward propellers. The tail unit was of conventional design, comprising a horizontal tail-plane and a single, vertical fin with rudder. Armament consisted of one 20 mm MG 151/20 cannon in a power-operated bow turret and three 7.92 mm MG 15 machine guns.
Only six aircraft were built and put into Luftwaffe service. They were used in the Norwegian campaign for transporting supplies, troops and wounded to and from the isolated German forces fighting at Narvik. During this campaign three of them were lost. Another Dornier Do 24C was lost on 16 November 1940, killing its crew, after being launched at night from the catapult ship “Friesenland” in Brest, France. The fate of two remaining aircraft, which in 1944 were still assigned to the “Erprobungsstelle” (Test Unit) in Travemünde, Germany, is unclear (Ref.: 24).

Blohm & Voss Bv 138C-1 (“Seedrache”, „Sea Dragon“), Supermodel

TYPE: Long-range maritime reconnaissance flying boat


POWER PLANT: Three Junkers Jumo 205D liquid-cooled, vertically opposed diesel engine, rated at 870 hp each

PERFORMANCE: 177 mph at 19,700 ft

COMMENT: Originally developed under the company name of Hamburger Flugzeugbau, the type was initially designated the Ha 138. Its appearance was unique in its combination of unusual design features with its twin boom tail unit, short fuselage and trimotor engine configuration. The short hull, with its hydrodynamic step beneath and flat sides, earned it the nickname “Der fliegende Holzschuh” (“The flying clog”).
Three piston engines were used. The central engine was mounted above the wing, driving a four-blade propeller, while the wing engines were lower, with three-blade propellers. The pre-production prototypes were powered by various makes of engines ranging from 650–1,000 hp. The first standardized version, BV 138B-1, was powered by three 868 hp Junkers Jumo 250D two-stroke, opposed-piston aircraft diesel engines. The engine cowlings also had an atypical appearance, due to the unique nature of the vertical orientation of the six-cylinder opposed-piston Jumo 205 diesel engines, and resembled the cowlings of 4 or 6-cylinder inverted inline engines found on smaller civil and utility aircraft from the Jumo 205’s propshaft placement, emerging forward at the uppermost front end of the power plant.
The booms of the twin tail unit, much like the smaller Focke-Wulf Fw 189 twin-engine reconnaissance monoplane, extended horizontally from the rear of the outer engine nacelles.
For hydrodynamic reasons, the hull featured a distinct “turn-down”, or “beak” at the stern. Two enclosed, powered gun turrets, each mounting a single MG 151/20 autocannon, were located prominently at the bow and stern. A third, fully open Scarf ring-like emplacement, behind the central engine and both above and forward of the rear turret, mounted a MG 131 heavy machine gun covered fields of fire obstructed from the other turrets by the horizontal stabilizer.
In all, 227 examples of standard service variants of the BV 138 were built. The first such variant, Bv 138C-1, began service in March 1941. While non-standard variants carried a variety of armament, the standard variant featured two 20 mm MG 151/20 cannons, one in a power-operated bow turret and one in a power-operated stern turret, up to three 7.92 mm MG 15 machine guns, and a 13 mm MG 131 machine gun in the aft center engine nacelle. It could carry up to 500 kg of bombs or depth charges (under the starboard wing root only) or, in place of these, up to 10 passengers. Both the B-1/U1 and C-1/U1 variants had racks under both wings to double the offensive load.
Some examples of the BV 138 were adapted to specialized roles. The Bv 138 was tested with the oft-used Walter HWK 109-500 “Starthilfe” (RATO) jettisonable rocket pod, used in pairs, for shorter take-off performance. One anti-shipping variant carried FuG 200 “Hohentwiel” low-UHF band maritime search radar. The BV 138 MS variant was converted for minesweeping (suffix “MS” means “Minen-Suchgerät”, “mine-search” aircraft, and carried magnetic field-generating degaussing equipment, including a hoop antenna with a diameter equal to the length of the fuselage, which encircled the hull and wings, which was also used on certain models of the Junkers Ju 52/3m trimotor transport used for the same duty (Ref. 24).