Category Archives: Imperial Army Air Force

Japan

Kawasaki Ki-78 (Planet, Resin)

TYPE: High-speed research aircraft

ACCOMMODATION: Pilot only

POWER PLANT: One Daimler-Benz DB 601A liquid-cooled piston engine, rated at 1,155 hp with Water/Methanol injection                  

PERFORMANCE: 435 mph at 11,500 ft

COMMENT: The Ki-78, designed at the Aeronautical Research Institute and built at Kawasaki Kokuki Kogyo K.K. to investigate flying behaviour at very high speed, featured a streamlined minimum cross-section fuselage fitted with a licence-built Daimler-Benz DB 601A engine. For short duration power boost methanol/water injection was used, and cooling was improved by a 60 hp turbine driven cooling fan for the radiators. By the outbreak of the war, the whole project was taken over by the Imperial Japanese Army who gave it the military type designation Ki-78. Kawasaki received the order to build two prototypes of the Ki-78, construction of which was started in September 1941. The first prototype was completed more than a year later and was flown for the first time on 26 December 1942. A feasibility study to improve the KI-78 flight performance showed that extensive airframe modifications were needed and consequently the project was officially terminated after the 32nd flight on 11 January 1944; the second Ki-78 was never completed (Ref.: 23).

Kawasaki Ki-60 (Airmodel, Resin)

TYPE: Interceptor fighter

ACCOMODATION: Pilot only

POWER PLANT: : One Daimler-Benz DB 601 liquid-cooled inverted V-12 engine, rated at 1,175 hp

PERFORMANCE: 348 mph at 14,800 ft

COMMENT: The Kawasaki Ki-60 was an experimental fighter that used a license-built German Daimler-Benz (Kawasaki) DB 601 liquid-cooled engine. This was at that time an unusual choice because the majority of Japanese aircraft used air-cooled radial engines. The Ki-60 was designed by Kawasaki Aircraft Industries in response to a 1939 Imperial Japanese Army Aviation Bureau requirement for a heavily armed specialised interceptor fighter to be powered by the liquid-cooled Daimler-Benz DB 601 inverted V12 engine, which had been selected for license production by Kawasaki as the Ha-40. A requirement was issued at the same time for a lighter, less heavily armed, general-purpose fighter which was to be designed almost in parallel with the Ki-60; this became the Kawasaki Ki-61 Hien. Priority was to be given to the Ki-60, design of which started in February 1940. The first prototype of the Ki-60 emerged in March 1941 as a compact monoplane with a relatively deep fuselage and tapered wings with rounded tips built around a system of three spars. The pilot’s seat was mounted high over the rear spar, giving the fuselage a distinctive “humped” profile; the hood featured a framed, rear sliding canopy and an elongated rear transparent section. The main coolant radiator was housed in a long ventral bath under the wing center-section and central fuselage, while the oil cooler was mounted under the engine with a long air intake. The prototype was powered by an imported Daimler-Benz DB 601A as production of the Ha-40 had not yet started. Although a top speed of 370 mph had been projected the Ki-60 was only able to achieve 341 mph. By this time the Nakajima Ki-44 Hajabusa, which had also been designed as a dedicated interceptor, was beginning to show some promise and the Koku Hombu selected this in fulfilment of its requirements. From early 1941 the full attention was focused on the Kawasaki Ki-61 Hien, but the Ki-60 became important in that the Ki-61 design was able to be improved using the lessons learned from the poor characteristics of the Ki-60. Plans for production were cancelled in late 1941 after three airplanes had been built. (Ref.: 23)

Nakajima Ki-44-II-Hei Shoki (Devil- Queller, Toyo), 70th Sentai (Hasegawa)

TYPE: Interceptor fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha-109 radial engine, rated at 1,520 hp

PERFORMANCE: 367 mph at 17,060 ft

COMMENT: The Ki-44-IIc variant of the Nakajima Shoki aircraft was armed with wing-mounted 20 mm Ho-3 cannon that proved particular effective against the B-29’s attacking Japan. But in December 1944, Shoki production terminated as the aircraft was replaced on Nakajima’s assembly-lines by the Nakajima Ki-84 Hayate and, when the war ended, only three Sentais were still equipped with them. In total 1, 225 Ki-44’s were built (Ref.: 1, 6)

Tachikawa Ki-106 (RS Models)

TYPE: Interceptor fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha-45-21 radial engine, rated at 1,990 hp

PERFORMANCE: 385 mph at 21.325 ft

COMMENT: Although the Nakajima Ki-84 Hayate was one of the most successful Japanese aircraft a modified version seemed to be necessary due to the increasingly critical light alloy supply situation as the war progressed. In late 1943 Tachikawa Hikoki K.K. were entrusted by the Ministry of Munitions with the task of designing an all-wood version of the Ki-84. Work on three airframes, designated Ki-106, began in autumn 1944, but various factors delayed the programme and the first of these prototypes was not to be completed and flown until July 1945. The Ki-106 was heavier than the standard Ki-84 what exerted an adverse effect on maneuverability and climb rate, but maximum level speed was virtually unchanged. The end of the war brought the Ki-106 project to a halt. (Ref.: 1., 6.)

Nakajima Ki-44-IIc-Otsu Shoki (Devil-Queller, Toyo), 87th Sentai, 2nd Chutai (Hasegawa)

TYPE: Interceptor fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha-109 radial engine, rated at 1,520 hp

PERFORMANCE: 367 mph at 17,060 ft

COMMENT: When China-based B-29s of the US XX Bomber Command, soon joined by Mariana-based Superfortresses of the XXI Bomber Command, began their bombing raids against Japan homeland, the Japanese Army had only one type of interceptor fighter on strength: The Nakjima Ki-44-IIb Shoki, (Devil-Queller) known as TOYO to Allied personel. The first prototype was completed and flown in August 1940 and production of the Ki-44-I started in in January 1942. As war progressed several variants were produced, so as Ki.44-II and Ki-44-III, all with several subtypes and more than nine Sentais and several Fighter Training Schools were equipped with the Ki-44. In late 1944, Shoki production terminated as the aircraft was replaced by the Nakajima Ki-84 Hayate (Ref.: 1).

Kawasaki Ki-119 (Unicraft, Resin)

TYPE: Suicide aircraft, Light bomber, Dive bomber and Escort fighter. Project.

ACCOMMODATION: Pilot only

POWER PLANT: One 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 defence 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 Imperial Japanese Army Air Force issued Kawasaki with orders to produce a single seat bomber that could carry 1,764lb of bombs to targets 373 miles (600km) from its base, armed with two 20mm cannon and powered by one 1,900ph Army Type 4 18-cylinder radial. 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. 1, 24).

Mansyu Ki-98 (A+V Models, Resin)

TYPE: Ground attack aircraft, fighter-bomber. Project

ACCOMODATION: Pilot only

POWER PLANT: One Mitsubishi Ha-211 Ru radial engine, rated at 2,200 hp

PERFORMANCE: 454 mph at 32.810 ft

COMMENT: In 1943 Mansyu offered the Japan Army Air Force a project of a single-seat ground attack aircraft designated Ki-98. The design was of twin boom configuration and was powered by a 2,200 hp turbosupercharged Mitsubishi Ha 211 Ru radial engine mounted in the central nacelle behind the pilot’s seat and driving a four-blade pusher propeller. Nose-mounted armament consisted of one 37 mm and two 20 mm cannon. A prototype was still under construction when Japan surrendered in September 1945 (Ref: 1)

Kogiken Plan III Revised Light Bomber (Unicraft, Resin)

TYPE: Light bomber. Project

ACCOMMODATION: Crew of two

POWER PLANT: Two radial engines, type not available

PERFORMANCE: No data available

COMMENT: Poorly documented JAAF-project of a light bomber with twin fuselage, two radial engines and pilot and gunner/radio-operator seated in the left fuselage. Similar designs during World War II were in Germany Arado E,580 (project), Messerschmitt Me 109Z (flown, Z for Zwilling = twin),  Messerschmitt Me 609 (project), Dornier Do 635 (Junkers Ju 8-635) (project),and Heinkel He 111Z (flown), and in the United States North American P-82 (flown).

Nakajima Ki-115 “Tsurugi” (Sabre) (MPM Model)

TYPE: Suicide attack aircraft

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha-35 radial engine, rated at 1,150 hp

PERFORMANCE: 342 mph at 9,185 ft

COMMENT: In January 1945, the Japanese Army instructed Nakajima to build a specially designed suicide attack aircraft. This was to be easy to build, maintain and fly, and provision had to be made in its design to carry a single bomb. Power was to be supplied by any air-cooled radial engine with a rating of 800 to 1,300 hp. Maximum speed was specified at 211 mph with the undercarriage in position and 320 mph after jettisoning.
The first prototype was completed in March 1945 and flight tests began immediately. As could be expected from such a crash program, the results were disappointing and several modifications were required before handing the aircraft to pilots with limited experience. Provision was made on the 104 production aircraft for two solid-fuel rockets under each wing to boost the aircraft’s speed in its final dive. None of these aircraft became operational before the war ended. (Ref 1.)

 

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

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)