Category Archives: Imperial Army Air Force

Japan

Fighter

Mitsubishi Ki-109b (2nd Chutai, 107th Sentai)(LS-Models)

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TYPE: Heavy interceptor

ACCOMMODATION: Crew of four

POWER PLANT: Two Mitsubishi Ha-104 radial engines, rated at 1,900 hp each

PERFORMANCE: 324 mph at 19,980 ft

COMMENT: In early 1943 the Mitsubishi Ki-67 heavy bomber then undergoing flight trials had proved that despite its size and weight it was fast and manoeuvrable. Consequently it was suggested that the Ki-67 be used as a basis for a hunter-killer aircraft. The project received the designation Ki-109 and two versions were built. The Ki-109a, nick-named “Killer”, was to mount in the rear fuselage two oblique-firing 37 mm Ho-203 cannon while the Ki-109b, the “Hunter”, was to be equipped with radar and a 40 cm search light. However, soon thereafter, the project was redirected and a standard 75 mm Type 88 anti-aircraft cannon was to be mounted in the nose. It was hoped that with this large cannon the aircraft could be able to fire on the Boeing B-29s while staying well out of range of their defensive armament. As the authorities anticipated that, initially at least, the B-29s would have to operate without fighter escort, the project was found sound and feasible and Mitsubishi were instructed in early 1944 to begin designing the aircraft which retained the Ki-109 designation.
Ground and inflight test firing of the heavy gun were sufficiently successful and an initial order of 44 aircraft was placed. Fifteen shells were carried for the 75 mm Type 88 cannon which were hand-loaded by the co-pilot, and the sole defensive armament consisted of a flexible 12.7 mm machine-gun in the tail turret. The rest of the airframe and the power plant were identical to those of the Ki-67. Despite the lack of high-altitude performance the Ki-109 was pressed into service, but, by the time enough aircrafts were on hand, the B-29s had switched to low-altitude night operations. A total of 22 Ki-109s were built by Mitsubishi Jukogyo K.K. (Ref.: 1).

Fighterbomber, Projects

Kogiken Plan V Revised Light Bomber (Unicraft, Resin)

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TYPE: Light bomber, fighter-bomber. Project

ACCOMMODATION: Crew of two

POWER PLANT: Two radial engines, rated at 1,450 hp each

PERFORMANCE: No data available

COMMENT: This design of a light bomber dates back to autumn 1941. A blueprint became available after the end of WW II showing a detailed three-view of the project and some important physical dimensions. It might be possible that this design may have had influence on the development of the Kawasaki Ki-102 (Allied code ‘Randy’). Furthermore, the design shows some similarity to the Grumman XP-50, forerunner of the Grumman F7F “Tigercat” (Ref.: 24).

Fighter, Fighterbomber

Nakajima Ki-43-II KAI ‘Hayabusa’, (‘Peregrine Falcon’, ‘Oscar’), 50th Sentai, 3rd Chutai, (Hasegawa)

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TYPE: Interceptor fighter, fighter bomber

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha.35/21 air-cooled radial engine, rated at 1.130 hp

PERFORMANCE: 320 mph at 19,680 ft

COMMENT:  Combat experiences with the Ki-43-I dictated a number of changes in the design of the aircraft that led to the development of the Nakajima Ki-43-II-KAI. It entered service in summer 1943 and served over every theatre to which the JAAF was committed. The Ki-43-II-KAI was capable to out-maneuvering every Allied fighter it encountered and its element was dog-fighting, but the Lockheed P-38 ‘Lightning’, the Republic P-47 ‘Thunderbolt’ and the north American P-51 ‘Mustang’ could all out-dive and out-zoom the Japanese fighter which could not withstand the greater firepower of the Allied types, frequently disintegrating in the air when hit. More than 5.000 Ki-43-II ‘Hayabusa’ were built by Nakajima and Tachikawa (Ref.: 13)

Fighter, Fighterbomber

Nakajima Ki-43-II-Otsu ‘Hayabusa’ (‘Peregrine Falcon’, ‘Oscar’) of Headquaters Chutai, 77th Hiko Sentai (Hasegawa)

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TYPE: Fighter, fighter bomber

ACCOMMODATION: Pilot only

POWER PLANT: One Nakajima Ha.115 radial engine, rated at 1,130 hp

PERFORMANCE: 320 mph at 19,680 ft

COMMENT: The Nakajima Ki-43 ‘Hayabusa’was a single-engine land-based tactical fighter used by the Imperial Japanese Army Air Force in WW II. It was light and easy to fly and became legendary for its combat performance in East Asia in the early years of the war. It could outmaneuver any opponent, but did not have armor or self-sealing tanks, and its armament was poor until its final version, which was produced as late as 1945. Allied pilots often reported that the nimble Ki-43s were difficult targets but burned easily or broke apart with few hits. In spite of its drawbacks, the Ki-43 shot down more Allied aircraft than any other Japanese fighter and almost all the JAAF’s aces achieved most of their kills in it. Prototypes for the Nakajima Ki-43-II flew in February 1942. The Ha-25 engine was upgraded with the 2-stage supercharger, thus becoming the more powerful Nakajima Ha-115 engine, which was installed in a longer-chord cowling. The new engine turned a three-bladed propeller. The wing structure, which had suffered failures in the Ki-43-I, was strengthened and equipped with racks for drop tanks or bombs. The Ki-43-II was also fitted with 13 mm armor plate for the pilot’s head and back, and the aircraft’s fuel tanks were coated in rubber to form a crude self-sealing tank. Nakajima commenced production of the Ki-43-II at its Ota factory in November 1942. Production was also started at the Tachikawa Hikoki KK and the 1st Army Air Arsenal (Tachikawa Dai-Ichi Rikugun Kokusho), also at Tachikawa. Although Tachikawa Hikoki successfully managed to enter into large-scale production of the Ki-43, the 1st Army Air Arsenal was less successful – hampered by a shortage of skilled workers, it was ordered to stop production after 49 Ki-43s were built. Nakajima eventually ceased production in mid-1944 in favor of the Nakajima Ki-84 ‘Hayate’, but the Tachikawa Hikoki continued to produce the Ki-43. Total production amounted to 5,919 aircraft. Many of these were used during the last months of the war for kamikaze missions against the American fleet (Ref.: 24).

Fighterbomber

Kawasaki Ki-102-Otsu (“Randy”), 45th Sentai, 3rd Chutai,(Pavla Models)

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TYPE: Ground-attack aircraft

ACCOMMODATION: Pilot and radio-operator

POWER PLANT: Two Mitsubishi Ha 112-II air-cooled radial engines, rated at 1,500 hp each

PERFORMANCE: 360 mph at 19,685 ft

COMMENT:  While the first prototype of the Kawasaki Ki-96 twin-engine heavy fighter was nearing completion the Kawasaki design team suggested to the Imperial Japanese Army that a version of the aircraft be built as a replacement for the Kawasaki Ki-45 “Toryu” used in ground attack role. In August 1943 after approval to the project the construction of prototypes began under the designation Kawasaki Ki-102. In its original two-seat configuration additional armour and petrol tank protection was fitted as well as a nose-mounted 37 mm Ho-203 cannon. The first of three prototypes was flown in March 1944. For production two versions were proposed, the Ki-102-Ko as high-altitude interceptor with Ru-102 turbo-superchargers and the Ki-102-Otsu ground attack aircraft without turbo-superchargers, a nose-mounted 57 mm Ho-401 cannon and two fuselage-mounted 20 mm Ho-5 cannon. In October 1944 the aircraft was placed in production. Most of the aircraft were kept in reserve in Japan, but a few saw limited action during the Okinawa campaign were the Ki-102-Otsu became known as Randy to the Allied forces. In total 238 Ki-102 aircraft were built, most of them as Ki-102-Otsu. By the end of 1944, when the B-29 operations against Japan were intensified, a specialized night-fighter version was developed as Kawasaki Ki-102-Hei. Only two prototypes were finished when WW II ended (Ref.: 1, 5).

Fighter, Fighterbomber

Kawasaki Ki-45-KAI-Otsu “Toryu”(“Dragon Killer”, “Nick”), 4th Sentai, 2nd Chutai, (Hasegawa)

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TYPE: Twin-engined heavy fighter, ground attack aircraft

ACCOMMODATION: Pilot and radio-operator/gunner

POWER PLANT: Two Mitsubishi Ha-102 radial engines, rated at 1,050 hp each

PERFORMANCE: 335 mph at 19,685 ft

COMMENT: The Kawasaki Ki-45-Kai Toryu was probably the most manoeuvrable twin-engined fighter to be employed operationally by any combatants during WW II.  Although outclassed in the air-to-air combat arena by Allied single-seat fighters, the Toryu was never to be considered an “easy kill” and it was to prove capable of out-manoeuvring the Lockheed P-38 “Lightning” without difficulty. Furthermore, the Ki-45 was very effective in ground attacks. A special version, the Ki-45-KAI-Otsu, was equipped with 20-mm Ho-3 cannon, too low-firing in air combat, but, as the Imperial Army enjoyed air superiority over the areas in which the Toryu was operating, it was found to be particularly efficacious in attacks on US Navy PT boats and other smaller vessels and in ground-attack role. In late 1943 the 20-mm Ho-3 cannon was replaced by a hand loaded 37-mm Type 98 gun, making this variant even more successful for close-support duties (Ref.: 5).

Fighter

Kawasaki Ki-108 (A + V Models, Resin)

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TYPE: Twin-engined high-altitude fighter

ACCOMMODATION: Pilot in pressure cabin

POWER PLANT: Two Mitsubishi Ha-112-II Ru radial engines, rated at 1,500 hp each

PERFORMANCE: 360 mph at 32,810 ft

COMMENT: In early 1943 intelligence reports concerning progress in the USA with the B-29 Superfortress recognized the Imperial Army Air Service that itself might eventually find confronted by bombers cruising above the effective combat ceiling of its existing fighters. So a requirement was prepared for a specialized heavy interceptor fighter capable of operating at extreme altitudes. Kawasaki proposed a derivative of its Ki-102, work on which just had commenced, featuring a pressure cabin for the pilot. As work proceeded the project was assigned the designation Ki-108. Two prototypes were ordered and flight trials began in mid 1944. Concerning the pressure cabin, it was calculated than an equivalent pressure of 9,845 ft could be maintained up to an altitude of 32,810 ft, but there were serious misgivings concerning the vulnerability of such a cabin to battle damage. These were answered in somewhat unexpected fashion, for, during early flight tests, an insecure lock resulted in the entry hatch blowing out at an altitude of some 33,000 ft with an immediate loss of pressure in consequence. The pilot immediately dived the aircraft and landed safely, indicating that the effect of a bullet penetration the pressure cabin would not be particularly hazardous. Further modifications resulted in the Kawasaki Ki-108-KAI (Ref.: 5).

Fighter, Fighterbomber, Nightfighter

Kawasaki Ki-45-KAI-Ko “Toryu”, (“Dragon Killer”, “Nick”), 5th Sentai, 1st Chutai, (Hasegawa)

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TYPE: Twin-engined heavy fighter, ground attack aircraft and night fighter

ACCOMMODATION: Pilot and radio operator/gunner

POWER PLANT: Two Mitsubishi Ha-102radial engines, rated at 1080 hp each

PERFORMANCE: 373 mph at 9,186 ft

COMMENT: The primary task of the Kawasaki Ki-45 “Toryu” , it’s design dates back to the late 1930th , was long-range escort of bombers. But it took a long time until the first pre-series aircraft were completed and flight testing initiated. Soon it became clear that the model has to be revised. This new aircraft, Ki-45-KAI (Kaizo means modified) was in fact a totally new design and performed completely satisfactory during its initial flight tests. Orders for quantity production were placed and the first aircrafts reached units by August 1942. The increasing use by the USAAF of B-24 Liberators by night called for improvisation on the part of the Imperial Army as the service possessed no specialized night fighters. The Ki-45-KAI-Ko was a choice for the nocturnal role and a field modification resulted in installation of a pair of Ho-103 machine guns or Ho-5 cannon mounted obliquely to fire upward and forward at an angle of some 70 degrees. While lacking AI radar and being forced to rely on ground guidance to intercept intruders, with searchlight illuminating the quarry, the Toryu enjoyed some success as a night fighter (Ref.: 5).

Nightfighter

Kawasaki Ki-102-Hei (“Randy”) (A+V Models, Resin)

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TYPE: Twin-engined night and bad weather fighter

ACCOMMODATION: Pilot and radar observer

POWER PLANT: Two Mitsubishi Ha-112-11 Ru supercharged radial engines, rated at 1,500 hp each

PERFORMANCE: 373 mph at 32,800 ft

COMMENT: In November 1944, at the time that Kawasaki had received instructions to produce 20 pre-production Ki-102-Ko interceptors, the company had also been ordered to develop as a matter of urgency a specialized night fighter version of the basic design. This, the Ki-102-Hei, retained the turbocharged engines but featured a longer-span wing, a lengthened fuselage, redesigned tail surfaces, the relocation of the second cockpit further aft, and an armament of two 30 mm Ho-105 cannon. Work on centimetric AI radar based on German FuG 240 Berlin N-1a had meanwhile proceeding in Japan, and provision was made in the Ki 102-Hei to mount the concave antenna dish behind a plexiglas nose cone. The first of two Ki-102-Hei prototypes was scheduled to commence its flight test programme in July 1945, with the second following one month later. But in June, the Kawasaki plant was again hit by B-29 Superfortresses and both Ki-102-Hei prototypes were seriously damaged. Repairs were begun immediately but Japan’s surrender terminated further work (Ref.: 5).

Fighter

Kawasaki Ki-96 (A+V Models, Resin)

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TYPE: Twin engine heavy fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two Mitsubishi Ha-12-11 radial engine, rated at 1,500 hp

PERFORMANCE: 391 mph at 31,170 ft

COMMENT: The great success of the Kawasaki Ki-45-KAI “Toryu” (“Dragon Slayer”, Allied code “Nick”) encouraged the Kawasaki Company to initiate work on a refined, more powerful derivative of the Ki-45. Compared with its forerunner an aerodynamically improved fuselage, a larger square-tipped vertical tail surface, and more powerful engines were provided. In 1943 work on the Ki-96 gained tempo and in September that year the first prototype was completed. In the meantime it became obvious that a second crew member was superfluous in a high-performance twin-engined fighter. So the second cockpit of the first prototype was faired over and the two other prototypes under construction were finished as single-seater. Flight test were most satisfactory, the Ki-96 combining good handling characteristics with performance exceeding design estimates. However, the Army’s interest in the potential of single-seat twin-engined fighters was to prove short-lived and consequently the Ki-96 had only a brief live as an aerodynamically prototype for the two-seat Kawasaki Ki-102 which supplanted it (Ref.: 1, 5).