World War II Database

Contributor: Alan Chanter

ww2dbaseThe Ki-67 Hiryu was without doubt the finest bomber to see service with the Imperial Japanese Army and Imperial Japanese Navy Air Forces during World War II, for it combined high performance with good defensive firepower, adequate offensive weapon load, and a structure that was both sturdy and provided good protection for the crew and fuel supply. Mitsubishi had submitted a design to a 1940 specification for a heavy bomber and in February 1941 was granted permission to develop and build three prototypes. The flight of the first of an eventual seventeen prototypes took place on 27 December 1942.

ww2dbaseThe Ki-67 was a cantilever mid-wing monoplane powered by two 1,900 hp Mitsubishi Ha-104 radial piston engines. The fuselage, with accommodation for a crew of six to eight, had a large bomb bay capable of carrying up to 1,764-lbs of bombs or one 1,765-lb (or 2,359-lb) torpedo. The normal defensive armament consisted of four (later five) 12.7mm machine guns and a 20mm cannon.

ww2dbaseService tests of the prototypes proved highly successful, but this resulted in the development programme becoming extremely protracted by the Army's insistence upon developing a whole range of variants to exploit the aircraft's excellent performance and handling. Production commenced on 2 December 1943 as the Army Type 4 Heavy Bomber Model I Hiryu (flying dragon) or Ki-67-1 and deliveries to Service Squadrons began during the summer of 1944 (after it was finally decided to concentrate production only upon a single version).

ww2dbaseAlthough production was seriously impaired by Allied air attacks on the factories, production would eventually total 698 aircraft. Mitsubishi would build 606 machines (29 of which were assembled by Nippon), Kawasaki built 91 and the 1st Army Air Arsenal (Tachikawa Dai-ichi Rikugun Kokusho) built 1 and modified two others as the, Ki.104 and Ki-109 experimental interceptors. The first 160 machines had torpedo racks and these operated successfully in both the bomber and torpedo-bomber roles. Some were converted as a three seat explosive-laden kamikaze aircraft (Ki-67-I KAI) and 22 machines were built, under the designation Ki-109, as a bomber interceptor mounting a 75-mm Type 88 cannon in a solid nose. The combat début of the Ki-109 proved a dismal failure; however, as without the turbo-superchargers originally specified, they were unable to engage the high-flying B-29s.

ww2dbaseThe Ki-67 (given the codename "Peggy" by the Allies) was deployed extensively in the final stages of the Pacific War especially in operation against Allied forces on Iwo Jima, the Marianas and Okinawa. Had the KI-67 entered service earlier and not generally been flown by mainly inexperienced crews, the story of the Pacific War might well have been very different.

Ki-67 Hiryu Timeline

SPECIFICATIONS

Ki-67-Ib

Machinery	Two Mitsubishi Ha-104 (Army Type 4) 18-cyl radial engines rated at 1,900hp each
Armament	1x20mm Ho-5 dorsal turret cannon, 1x12.7mm nose Ho-103 Type 1 cannon, 2x12.7mm fuselage Ho-103 Type 1 cannon, 2x12.7mm tail Ho-103 Type 1 cannon, 1,600kb of bombs or one torpedo (up to 2,900kg of explosives as special attack aircraft)
Crew	8
Span	22.50 m
Length	18.70 m
Height	7.70 m
Wing Area	65.85 m²
Weight, Empty	8,650 kg
Weight, Maximum	13,765 kg
Speed, Maximum	537 km/h
Speed, Cruising	400 km/h
Service Ceiling	9,470 m
Range, Normal	3,800 km

Photographs