The Ki-100 was a result of the development of the Ki-61-II being heavily hampered by a number of factors, which would also affect the aircraft itself. So when the Kawasaki Ki-100 did finally enter
service it arrived too late to make any impact on the air war during World War 2.
1st February 1945
The roots of the Ki-100 lay in another Kawasaki aircraft the Ki-61-II which was being used as a high-altitude interceptor to attack the high flying Boeing B-29 Superfortress being used at altitudes
of around 30,000 ft by the United States. The Ki-61-II was only considered as a stop gap and was powered by the still in development 1,500-hp Kawasaki Ha-140 engine. However the Akashi factory
which was manufacturing the engine would be destroyed as a result of an air raid meaning the engine program was cancelled.
As a result of the Ha-140 engine program being abandoned there were 275 Ki-61-II airframes left without engines. Kawasaki were tasked with finding another engine to be installed instead. The major
issue was that the aircraft was designed for an inline engine and no alternative was available. The decision was taken to modify three of the excess airframes to take the Mitsubishi Ha-112 II
radial engine which provided the same power as the Ha-140.
Making its maiden flight on the 1st February 1945 the aircraft impressed Kawasaki and work started on converting the remaining 272 airframes which would be completed by the end of May, with the
first aircraft entering service during March 1945. The aircraft in its new configuration would be called the Ki-100 with this variant designated Ia. Although when it entered service with the
Imperial Japanese Army it was known as the Type 5 Fighter Model 1A.
Two more Ki-100 variants were produced before the increasing air attacks by the United States Army Air Force and the end of World War 2 brought production to a halt. The first was the Ki-100-Ib, of
which 99 were produced, which would have an all-round-view canopy installed. This had originally been designed to be fitted to the intended Ki-61-III design which never entered production. Its rear
fuselage was cut down as well. The next version would see just three prototypes built for what was to be the Ki-100-II. The turbocharged Mitsubishi Ha-112-IIru which would provide better
performance at high-altitude was to power these aircraft.
In total 377 aircraft would be modified or built as Ki-100s.
Click on the aeroplane image to view a larger version.
||two 12.7mm Ho-103 machine-guns
two Ho-5 cannons
||Only 3 prototypes produced.
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(C) = Cockpit only exhibit. (F) = Fuselage only exhibit. (R) = Remains of an aircraft.