Жапон әскери ұшағы: Ки-100 моделі

Japanese fighter aircraft

The Kawasaki Ki 100 (キ100) is a single seat single engine monoplane fighter aircraft used by the Imperial Japanese Army Air Service (IJAAS) during World War II. The Japanese Army designation was "Type 5 Fighter" (五式戦闘機). It was not assigned an Allied code name. In early 1945, 275 Ki 100s were modified from Ki 61s as an emergency measure to accept a 14 cylinder Mitsubishi Ha 112 II radial engine in place of the original Kawasaki Ha 40 inverted V 12 inline engine, resulting in one of the best interceptors used by the Army during the war. It combined excellent power and maneuverability, and from the first operational missions in March 1945 until the end of the war, it performed better than most IJAAS fighters against both United States Army Air Forces B 29 Superfortress bombers and P 51 Mustang fighters, as well as U. S. Navy F6F Hellcat carrier fighters. A newly built variant, the Ki 100 Ib, was produced with a cut down rear fuselage during the last months of the war which equipped five home defence sentai. High altitude performance was further improved with the final variant, the Ki 100 II, however only three of these were produced before the war ended and this final variant never saw operational service.

The Ki 100 was a stressed skin cantilever low wing single seat enclosed cockpit radial engine monoplane fighter with retractable undercarriage. Control surfaces were fabric covered.

In mid 1944, the Ki 61 was one of the best fighters of the Imperial Japanese Army Air Service (IJAAS). It was also the only production Japanese fighter to have an inline powerplant, the V 12 Kawasaki Ha 40, a Japanese adaptation of the German Daimler Benz DB 601 engine, as well as one of the first with factory installed armor and self sealing fuel tanks. It also had a respectable performance, in line with contemporary American designs, with speed and rate of climb emphasized instead of manoeuvrability and range. It was an effective design, but suffered from engine shortages and reliability problems. These problems led to the development of an improved model, the Ki 61 II (later Ki 61 II KAI), powered by the improved Kawasaki Ha 140 inverted V 12 engine, which was heavier than the Ha 40 it replaced. Maximum speed increased from and aside from the rate of climb, general performance was improved as well. However, it never performed as expected due to continued quality control problems with the engine, while far fewer engines were produced than required.

At this point of the war, the IJAAS was in desperate need of effective interceptors to stop bombing raids over the Japanese mainland, so in October 1944 a decision was made to use the Mitsubishi Ha 112 II (Kinsei ["Venus"] 60 series), a 14 cylinder, two row radial engine. The need for a new engine became urgent on 19 January 1945, when a bombing raid destroyed the Ha 140 production plant, leaving 275 otherwise complete Ki 61s engineless. The Mitsubishi Ha 112 II was lighter than the Ha 140 and developed the same power but with much greater reliability. Three Ki 61 II KAIs were modified to carry this engine as prototypes. Chief engineer Takeo Doi with two other engineers redesigned the Ki 61 airframe to accept the new engine. Their solution was to use a second skin to form a fairing riveted to the fuselage to smooth out the airflow behind the cooling flaps and multiple exhaust stubs of the new engine cowling. As this engine was lighter, they were able to remove the lead counterweight in the tail that balanced out the heavier Ha 140 engine. The new model was flown for the first time on 1 February 1945. Without the need for the heavy coolant radiator and other fittings required for a liquid cooled engine, the Ki 100 was lighter than the Ki 61 II, reducing the wing loading from 189 kg/m2 (38.8 lb/ft2) to 175 kg/m2 (35.8 lb/ft2). This had a positive effect on the flight characteristics, enhancing landing and takeoff qualities as well as improving manoeuvrability and reducing the turning radius.

The Ki 100 I Otsu were newly built as such, rather than being conversions, with a cut down rear fuselage and improved canopy and 118 were produced from May through to the end of July 1945. This version also featured a modified oil cooler under the engine in a more streamlined fairing. Due to a lack of space no intercooler was installed; however, performance was still enhanced above .