AP 118 · No. 10 Section II · Aircraft Plate 151 / 334

Plate 151 of 334 · Second World War · Fighter

Kawasaki Ki-61-II KAI Hien

Ki-61-II KAI 6117, painted as Kawasaki Ki-61-II KAI Hien production No. 6117 (long published as 5017), the only surviving Ki-61, as displayed at the Kakamigahara Air and Space Museum, Gifu, after its restoration by Kawasaki Heavy Industries in 2015–16: a slim single-seat fighter with a licence-built Daimler-Benz inverted-V12 under a long pointed cowling with rows of exhaust stubs, a three-blade propeller, a ventral radiator bath under the centre fuselage, a long, slender, high-aspect-ratio wing with rounded tips, a razorback rear fuselage behind a framed canopy and a tall rounded fin and rudder, shown tail down on its wheels: unpainted bare aluminium in a patchwork of brighter and duller panels, doped-silver fabric ailerons, elevators and rudder, blue-green aotake in the wheel wells and on the inner faces of the undercarriage doors, black main legs, bare-metal spinner and blades with a red-brown ring at the back of the spinner, and no national markings, as photographed on display (no Ki-61 is in a UK museum; shape from a Ki-61-I three-view with the II KAI’s longer nose and razorback tail taken from Ki-100 drawings, checked against photographs of this aircraft; the pattern of light and dark panels and the starboard exhaust row are approximated).

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as Kawasaki Ki-61-II KAI Hien production No. 6117 (long published as 5017), the only surviving Ki-61, as displayed at the Kakamigahara Air and Space Museum, Gifu, after its restoration by Kawasaki Heavy Industries in 2015–16: a slim single-seat fighter with a licence-built Daimler-Benz inverted-V12 under a long pointed cowling with rows of exhaust stubs, a three-blade propeller, a ventral radiator bath under the centre fuselage, a long, slender, high-aspect-ratio wing with rounded tips, a razorback rear fuselage behind a framed canopy and a tall rounded fin and rudder, shown tail down on its wheels: unpainted bare aluminium in a patchwork of brighter and duller panels, doped-silver fabric ailerons, elevators and rudder, blue-green aotake in the wheel wells and on the inner faces of the undercarriage doors, black main legs, bare-metal spinner and blades with a red-brown ring at the back of the spinner, and no national markings, as photographed on display (no Ki-61 is in a UK museum; shape from a Ki-61-I three-view with the II KAI’s longer nose and razorback tail taken from Ki-100 drawings, checked against photographs of this aircraft; the pattern of light and dark panels and the starboard exhaust row are approximated). Drag to orbit, scroll or pinch to zoom · download .glb (1.1 MB)

Data plate

Specification

First flight, number built and top speed are for the whole family (Ki-61-I & II (Allied name ‘Tony’)); engine, crew and dimensions are for the Ki-61-II KAI 6117 modelled here.

History

The Hien

Kawasaki bought a licence for the Daimler-Benz DB 601 in the late 1930s and built it as the Ha-40, and the Imperial Japanese Army asked the company for a fighter to use it. Takeo Doi’s team designed a slim, clean low-wing monoplane with a long, high-aspect-ratio wing for range and climb, a radiator bath under the centre fuselage, armour and self-sealing tanks, all of which most Japanese fighters of the time lacked. The first prototype flew in December 1941, and the type was adopted as the Army Type 3 Fighter and named Hien, ‘flying swallow’.

It went into combat over New Guinea in the spring of 1943 with the 68th and 78th Sentai. It was the only Japanese fighter of the war with a liquid-cooled inline engine to be built in large numbers, and its pointed nose led Allied intelligence at first to take it for a licence-built Italian or German type; it was given the code name ‘Tony’. It could dive and take punishment better than the nimble Ki-43, but the Ha-40 was unreliable in tropical heat and short of spares, and serviceability was often poor. Later Ki-61-Is carried two 20 mm cannon in the wings, at first German Mauser MG 151s brought to Japan by submarine.

The Ki-61-II, flown in December 1943, had the more powerful Ha-140 and a bigger wing; in its production form, the Ki-61-II KAI, it went back to the original wing but had a longer fuselage and a larger rudder. Its engine was even less reliable than the Ha-40, and when American bombing destroyed the Akashi engine factory in January 1945 some 275 finished airframes were left without engines; they were fitted with radials and became the Ki-100. In all 3,078 Ki-61s were built. Over Japan in 1944–45 Hien units such as the 244th Sentai fought the B-29s, some pilots ramming the bombers deliberately. None is in a UK museum.

This airframe

Ki-61-II KAI 6117

6117The airframe modelled

This Ki-61-II KAI is the only Ki-61 left in the world. It was long published as c/n 5017, but its restoration identified it as production No. 6117. It survived the war in Japan and was displayed for many years at the Chiran Peace Museum for Kamikaze Pilots in Kagoshima. In 2015 it went to Kawasaki Heavy Industries, the company that built it, for restoration; it was shown at Kobe in October 2016 for Kawasaki’s 120th anniversary and is now displayed at the Kakamigahara Air and Space Museum in Gifu, beside the airfield where Kawasaki flew its fighters during the war. The restorers stripped the old paint, and the model shows the aircraft as it is displayed: unpainted bare aluminium in a patchwork of brighter and duller panels, doped-silver fabric ailerons, elevators and rudder, blue-green aotake lacquer in the wheel wells and inside the undercarriage doors, black main legs, and a bare-metal spinner and blades with a red-brown ring at the back of the spinner. It carries no national markings; red discs seen in some photographs are light from the museum’s display lighting. Its shape comes from a Ki-61-I three-view, with the II KAI’s longer nose and its rear fuselage and tail checked against Ki-100 drawings, which share the airframe, and against photographs of this aircraft. The pattern of light and dark panels is approximated, and the starboard exhaust row, hidden by the wing in photographs, is assumed to match the port side.

Where to see one

Not on charge

A Ki-61-II is displayed at the Gifu-Kakamigahara Air and Space Museum in Japan. None is in a UK museum.

All 334 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.