World War II Database

Contributor: Alan Chanter

ww2dbaseDerived from the Ki-96 twin-engine single-seat heavy fighter project, development of which had been abandoned after three prototypes had been completed, the Ki-102 was intended as a two-seat attack fighter for primary deployment in a close-support role. Retaining the wings, tail assembly and engines of the KI-96 design, work commenced in August 1943 with the first of three prototypes completed in March 1944. A cantilever mid-wing monoplane, with a conventional tail unit, retractable tail-wheel landing gear and powered by two Ha-112-II radials the Ki-102's two-man crew was accommodated in separate enclosed cockpits in tandem. Twenty pre-production Ki-102 were built for service trials and in October 1944 production of 215 aircraft were ordered under the official designation of Army Type 4 Assault Fighter.

ww2dbaseArmed with a 57-millimeter Ho-401 cannon in the nose, two 20-millimeter Ho-5 cannons under the fuselage and a rear firing 12.7-millimeter Ho-103 (Type 1) machine gun in the rear cockpit for the observer, one of the pre-production aircraft had an early opportunity to demonstrate the potency of its large-calibre cannon when it shot an engine off a passing B-29 Superfortress with one shell.

ww2dbaseAllocated the Allied code-name "Randy" the aircraft saw little operational service apart from some limited use over Okinawa. Most were held in reserve in Japan where some were used to trial the rocket powered Igo-1-B (Kawasaki Ki-148) radio-controlled guided missile.

ww2dbaseThe urgent need for high-altitude interceptors to attack the American bomber fleets brought the conversion of six pre-production Ki-102s with the designation of Ki-102-Ko and powered by turbocharged Ha-112-IIru engines producing 1370 horsepower at 7000 metres. The Ki-102-Ko differed from the Ki-102-Otsu ground-attack fighter by having improved two-seat accommodation, a revised tail unit and armament of one 37-millimeter Ho-203 cannon and two 20-millimeter Ho-5 cannon. The first Ki-102-Ko was tested in June 1944, and in November the highest priority was given to the quantity production of the fighter. Unexpected problems with the turbocharged engines, however, resulted in many production delays and only fifteen fighters were completed before the war ended.

ww2dbaseWith the intensification of night attacks on the Japanese Home Islands at the end of 1944, the basic design was modified for the night fighter role as the Ki-102-Hei. This model was to have an increased wingspan, lengthened fuselage, redesigned tail surfaces, a relocated second cockpit, a primitive AI radar placed above the fuselage and two forward-firing 30-millimeter Ho-105 cannon beneath the fuselage. Two 20-millimeter Ho-5 cannon mounted to fire obliquely forward and upwards were also located in the rear fuselage. Air attacks by B-29 Superfortresses, however, hampered production to such an extent and only two prototypes Ki-102-Hei night fighters were ever completed and probably did not enter service.

ww2dbaseAnother planned variant of the basic Ki-102 airframe with the structural improvements of the Ki-102-Hei was the proposed Kawasaki Ki-108 fitted with a single-seat pressurised cockpit for specialised operations at extreme altitudes. Its armament would consist of one 37-millimeter and two 20-millimeter cannon. Flight trials of a converted Ki-102 began in July 1944 without the turbochargers fitted and by late 1944 the enlarged fuselage of the Ki-102-Hei was installed on this test machine. Two new prototypes, derived from the seventh and eighth pre-series Ki-102 airframes, were now built, these being designated Ki-108 Kai, The first of these being completed in March 1945, but their flight testing was still incomplete when the Pacific war ended.

SPECIFICATIONS

Ki-102b

Machinery	Two 1,500hp Mitsubishi Ha-112-II (Type 4) 14cyl air-cooled radial piston engine
Armament	1x57mm Ho-401 cannon, 2x20mm Ho-5 cannon, 1x12.7mm Ho-103 trainable machine gun at rear cockpit, 1,100lb bomb load or 2x200l drop tanks on underwing racks
Crew	2
Span	15.57 m
Length	11.45 m
Height	3.70 m
Wing Area	34.00 m²
Weight, Empty	4,950 kg
Weight, Loaded	7,300 kg
Speed, Maximum	580 km/h
Service Ceiling	11,000 m
Range, Normal	2,000 km

Photographs