Category Archives: Imperial Army Air Force

Japan

Fighter, Fighterbomber

Rikugun Ki-93-Ia (A+V Models, Resin)

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TYPE: Twin-engined heavy fighter and ground attack aircraft

ACCOMMODATION: Crew of two

POWE PLANT: Two Mitsubishi Ha-214 radials, rated at 2,400 hp each

PERFORMANCE: 388 mph at 27,230 ft

COMMENT: The Rikugun Ki-93 was the last heavy fighter and ground-attack aircraft built in Japan during WW II and was the only design of the Rikugun Kogugijutsu Kenkyujo (Army Aerotechnical Research Institute) to be flown. Powered by two 2,400 hp Mitsubishi Ha-214 air-cooled radials driving six-blade propellers, the aircraft was designed specially to carry large caliber cannon in its under-fuselage gondola. Thus the Ki-93 was designed to perform as a high-altitude heavy bomber destroyer as well as a low-altitude anti-shipping aircraft. In its bomber destroyer form (Ki-93-Ia ) the aircraft carried offensive armament comprising one 57 mm Ho-401 cannon and two 20 mm Ho-5 cannon, while for the anti-shipping missions its offensive armament  comprised one 75 mm Type 88 cannon and two 250 kg bombs (Ki-93-Ib).
Production of the Ki-93 was entrusted to the Dai-Ichi Rikugun Kokusho (First Army Air Arsenal) at Tachikawa and the first prototype was completed and flown in April 1945. A second prototype, the Ki-93-Ib in ground attack configuration, was completed but not flown before the end of the hostilities. (Ref.: 1)

Fighter, Fighterbomber

Nakajima Ki-84-I-Ko Hayate, 1st Chutai, 102nd Hiko Sentai (Hasegawa)

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TYPE: Fighter, Fighterbomber

ACCOMMODATION: Pilot only

POWER PLANT: Nakajima Ha-45 engine, rated at 1,990hp

PERFORMANCE: 392 mph at 20,080 ft

COMMENT: In June 1943 some of the first Nakajima Ki-84-Ia  Hayate of a service trials batch of 83 machines were handed over to the Tachikawa Army Air Arsenal for service tests. During flight trials the Ki-84 reached a top speed of 388 mph, climbed to 16,405 ft in 6 min 26 sec and reached a service ceiling of 40,680 ft, thus demonstrating the best performance of any Japanese aircraft suitable for immediate production. A second pre-production batch of 42 Ki-84s was built in April 1944 and in the following months more and more aircraft were delivered to several Sentai. In combat it became obvious that the Ki-84 was a formidable foe , comparing favourably with the best Allied fighters. (Ref.: 1)

Fighter, Fighterbomber

Nakajima Ki-84-Ia Hayate, Chutai 29th Hiko Sentai (Hasegawa)

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TYPE: Fighter, Fighterbomber

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha-45 engine, rated at 1,999 hp

PERFORMANCE: 392 mph at 20,080 ft

COMMENT: Undoubtedly the best Japanese fighter aircraft to see large-scale operation during the last years of war in the Pacific Area, was well protected, well armed, fast and manoeuvrable. The Ki-43 Hayabusas were just starting to fire their guns in anger when Nakajima was instructed to design their replacement. The specification called for an all-purpose, long-range fighter with high speed and capable of operating at combat rating for 1.5 hours. Design work was initiated in early 1942 and in March 1943 the first prototype was completed. Flight test began in April 1043 and after success under operational conditions the mass production of the aircraft war started as Army Type 4 Fighter Model 1A Hayate, or Ki-84-Ia. A total of 3,514 Ki-84s and derivatives were built, of which were 3,288 Ki-84-I and Nakajima Ki-84-II production aircraft as well as 3 Tachikawa Ki-106 prototypes, a wooden version of the Ki-84 Hayate. (Ref.: 1)

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).

Fighter, Projects

Kawasaki Ki-88 (Unicraft, Resin)

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TYPE: Fighter, fighter bomber

ACCOMMODATION: Pilot only

POWER PLANT: One Kawasaki Ha-140 liquid-cooled engine, rated at 1,500 hp

PERFORMANCE: 373 mph at 19,685 ft

COMMENT: The Kawasaki Ki 88 was designed as a fighter aircraft and inspired by the Bell P-39 Airacobra. Work on the design began in 1942 and by 1943 a full-scale mock-up was completed. The engine was mounted behind the cockpit, driving a tractor propeller via an extension shaft. Proposed armament comprised a 37 mm cannon in the propeller shaft and two 20 mm cannon in the lower section of the nose. Calculation suggested no great improvement on that of the Kawasaki Ki-61 Hien already in production, and so the project was abandoned during 1943 (Ref.: 1).

Fighter, Projects

Nakajima Ki-62 (Unicraft, Resin)

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TYPE: Interceptor fighter. Project.

ACCOMMODATION: Pilot only

POWER PLANT: One Kawasaki Ha-40 liquid-cooled engine, rated at 1,175 hp

PERFORMANCE: 370 mph at 15,950 ft (estimated)

COMMENT: The Nakajima Ki-62 was a light fighter designed in 1941 to compete with the Kawasaki Ki-61 “Hien”. Although this design appeared to be promising, its development was discontinued to enable Nakajima to concentrate on production of their Ki-63 “Hayabusa” and Ki-44 “Shoki” fighters. Later, the Ki-62’s data and design features were incorporated in the Nakajima Ki-84 “Hayate” design (Ref.: 1).

Fighter

Nakajima Ki-87 (Pavla Models)

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TYPE: High-altitude interceptor fighter

ACCOMMODATION: Pilot in pressurized cockpit

POWER PLANT: One Nakajima Ha-44 radial engine, rated at 2,200 hp

PERFORMANCE: 439 mph at 36,090 ft (estimated)

COMMENT: The Nakajima Ki-87 was developed in response to American Boeing B-29 “Superfortress” raids on the Home Islands. It followed up on earlier research by Nakajima and the Technical Division of Imperial Army Headquarters into boosting a large radial engine with an exhaust-driven turbo-supercharger, which had begun in 1942, well before the B-29 raids began. The efforts of the Technical Division of Imperial Army Headquarters eventually culminated into the Tachikawa Ki-94-I, while the Nakajima Ki-87 was developed as a fall-back project, using less stringent requirements. Nakajima started in July 1943 with the construction of three prototypes, to be completed between November 1944 and January 1945, and seven pre-production aircraft, to be delivered by April 1945. The Technical Division of Imperial Army Headquarters made itself felt during the development of the Ki-87 prototype when they insisted upon placing the turbo-supercharger in the rear-fuselage, and from the sixth prototype the Nakajima fighter was to have that arrangement. The Ki-87 had a rearward folding undercarriage to accommodate the storage of ammunition for the cannons, which were mounted in the wing.
Construction was delayed due to problems with the electrical undercarriage and the turbo-supercharger, and the first prototype was not completed until February 1945; it first flew in April, but only five test flights were completed, all with the undercarriage in the extended position. Production of 500 aircraft was planned, but the war ended before any more than the single prototype was built.
A further variant, the Nakajima Ki-87-II, powered by a 3,000 hp Nakajima Ha-217 (Ha-46) engine and with the turbo-supercharger in the same position as the USAAF Republic P-47 “Thunderbolt”, never went further than the drawing board (Ref.: 24).

Fighter

Mitsubishi Ki-83 (MPM)

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TYPE: Long-range fighter

ACCOMMODATION: Pilot and navigator

POWER PLANT: Two Mitsubishi Ha 211 Ru (Ha-43) radial engines, rated at 2,070 hp each

PERFORMANCE:  438 mph at 32,180 ft

COMMENT: The Mitsubishi Ki-83 was designed as a long-range heavy fighter. The design was a response to a 1943 specification for a new heavy fighter with great range. The first of four prototypes flew on 18 November 1944. The machines displayed remarkable maneuverability for aircraft of their size and carried a powerful armament of two 30 mm and two 20 mm cannon in its nose. Despite the bomb-ravaged Japanese manufacturing sector, plans for the Ki-83 to enter production within were underway when Japan surrendered on 15 August 1945.
Both the existence and performance of the Ki-83 were little known during the war, even in Japan. It was completely unknown in Allied military aviation circles – as demonstrated by the fact that the Ki-83 had not been given a reporting name. Most early photographs of the type were taken during the post-war occupation of Japan, when the four prototypes were seized by the USAAF and re-painted with USAAF insignia. When they were evaluated by US aeronautical engineers and other experts, a Ki-83 using high-octane fuel reached a speed of 473 mph at an altitude of 23,000 ft (Ref.: 24).

Projects

Mitsubishi Ki-73 “Steve” (Unicraft, Resin)

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TYPE: Long-range escort fighter. Project

ACCOMMODATION: Pilot only

POWER PLANT: One Mitsubishi Ha 203-II liquid-cooled engine, rated at 2,600 hp, driving three-bladed contra-rotating propellers

PERFORMANCE:  466 mph

COMMENT: During May 1943, Japanese authorities delivered a new requirement for a single-seat, single-engine long range escort fighter to protect bomber formations from interception by Allied warplanes beginning to gain the advantage in the skies over the Pacific Area of Action. The Mitsubishi Ki-73 was one result of the requirement by the type was not furthered beyond a sole, incomplete prototype before the end of WW II. The design team managed to find success with the earlier twin-engine Mitsubishi Ki-46 “Dinah” and eventually moved on to the promising Mitsubishi Ki-83 twin-engine, two seat long-range heavy fighter design of which four prototypes ultimately emerged when the development of the Ki-73 was abandoned. Rather unique for Japanese-originated wartime fighter design was the use of contra-rotating propeller arrangement. The rest of the overall design arrangement was conventional – the engine in the nose, a single-finned tail at rear and cockpit set over center mass. Wings were straight monoplane appendages with clipped tips and tailwheel undercarriage was fully retractable. While the Mitsubishi Ki-73 was never formally adopted for service and never entered serial production, captured documents by the  Allies – who believed the type was to come online soon – allocated the codename “Steve” for the series which never was.

Fighter

Kawasaki Ki-64 (“Rob”), (MPM)

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TYPE: Heavy fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Kawasaki Ha-201 coupled liquid-cooled engines, rated at 2,350 hp

PERFORMANCE: 430 mph at 16.000 ft

COMMENT: The Kawasaki Ki-64, Allied code name “Rob”, was a one-off prototype of an experimental heavy, single seat, fighter. It had two unusual design features. First; it had two Kawasaki Ha-40 engines in tandem; one in the aircraft nose, the other behind the cockpit, both being connected by a drive shaft. This combination, called the Kawasaki Ha-201, drove two, three-bladed, contra-rotating propellers. The second feature was the use of the wing surface as a radiator for the water-cooled engines. The aircraft first flew in December 1943. During the fifth flight, the rear engine caught fire; and while the aircraft made an emergency landing, it was damaged. The aircraft was subsequently abandoned in mid-1944 in favour of more promising projects. The airframe survived the war, and parts of the unique cooling system were sent to Wright Field in the US for examination (Ref.: 24).