Mitsubishi Ki-67

Ki-67 "Hiryu"
Role Medium bomber
Manufacturer Mitsubishi
Designer Ozawa Kyonosuke
First flight 27 December 1942
Primary users Japanese Imperial Army
Japanese Imperial Navy
Number built 767

The Mitsubishi Ki-67 Hiryū (飛龍, "Flying Dragon"; Allied reporting name "Peggy") was a twin-engine medium bomber produced by Mitsubishi and used by the Imperial Japanese Army Air Force in World War II. Its Army designation was "Type 4 Heavy Bomber" (四式重爆撃機).

Contents

Design

The Ki-67 was the result of a 1941 Japanese army specification for a successor to the Nakajima Ki-49. This new aircraft was specified to be a high-speed twin-engined heavy bomber suitable for possible conflicts with the Soviet Union over the Manchuria-Siberia border, and unlike many Japanese warplanes, was required to have good defensive armament and the ability to survive heavy battle damage. It was also required to be highly maneuverable allowing it to carry out dive-bombing attacks and escape at low level.[1][2] and was first encountered by Allied forces in a sea battle off Formosa in October 1944.

The Ki-67 was designed by a team led by Ozawa Kyonosuke, chief engineer at Mitsubishi, and was a mid-winged monoplane of all-metal construction, with a retractable tailwheel undercarriage. It was fitted with self-sealing fuel tanks and armor,[2][3] features common in US fighters and bombers but frequently lacking in Japanese aircraft. With these features and its two 1,417 kW (1,900 hp) 18-cylinder air-cooled radial engines, the Ki-67 was perhaps one of the most sturdy and damage-resistant Japanese aircraft of World War II.

The Ki-67's bomb load of 1,070 kg (2,360 lb) (carried in its internal bomb bay) would classify it as a medium bomber for the US (the B-25 Mitchell could carry up to 2,722 kg (6,000 lb), the B-26 Marauder up to 1,814 kg (4,000 lb), and the A-20 Havoc up to 907 kg (2,000 lb), for example). Its performance was remarkable compared to US medium bombers; the Ki-67 had a level-flight top speed of 537 km/h/334 mph (against 443 km/h/275 mph for the B-25, 462 km/h/287 mph for the B-26, and 538 km/h/338 mph for the A-20), good maneuverability in high-speed dives (up to nearly 644 km/h/400 mph), excellent sustained rate of climb, and outstanding ability to turn (excellent turn rate, small turn radius, and ability to turn at low speeds). The maneuverability of the Ki-67 was so good that the Japanese used the design as the basis for the Ki-109 twin-engine fighter, originally designed as a night fighter, and later for use as a daylight heavy fighter. In the last stages of World War II, the Japanese Navy also used the design as the basis for the Q2M1 "Taiyo" radar-equipped anti-submarine aircraft.

Another interesting feature of the Ki-67 was that the gun in the dorsal gunner's turret position was a 20 mm cannon. (In addition to twin 12.7 mm/0.5 in machine guns in the tail, one 12.7 mm/0.5 in gun in the nose, and one 12.7 mm/0.5 in gun at each waist-gun position.) The 20 mm cannon is an unusually powerful defensive armament for a bomber. Until the introduction of the B-29 Superfortress, US bombers seldom had cannons in defensive gunner positions, instead typically having one or two 12.7 mm (0.5 in) machine guns.

Operations

The Ki-67 was used for level bombing and (as the Yasakuni Type) torpedo bombing (it could carry one torpedo attached under the fuselage). The Ki-67 was initially used by the Japanese Army and Navy Air Services against the US 3rd Fleet during its strikes against Formosa and the Ryukyu Islands. It was later used at Okinawa, in Mainland China, French Indochina, Karafuto and against B-29 airfields in Saipan, Tinian, and Guam in support of Giretsu (a special unit of the Japanese Imperial Army) strikes. One special ground-strike version used in the Giretsu missions was a Ki-67 I with three remote-control 20 mm cannons angled at 30° for firing toward the ground, a 20 mm cannon in the tail, 13.2 mm (.51 in) machine guns in the lateral and upper positions, and more fuel capacity. Even with more fuel, the Giretsu missions were one-way only because of the long range. In the last stages of World War II, special attack versions of the Ki-67 (the I KAI and Sakura-dan models) were used in kamikaze missions. (References include information from Lt. Sgt. Seiji Moriyama, a crew member in Fugaku Special Attack Unit, who witnessed Ki-67's being converted into To-Go suicide planes with two 800 kg/1,760 lb bombs during Okinawa operations.)

By the end of World War II, 767 Ki-67s had been produced. Other sources relate that 698 Ki-67's were manufactured, excluded the KAI and Sakura-dan conversions.

Variants

Specifications (Ki-67-Ib)

Data from Japanese Aircraft of the Pacific War[4]

General characteristics

Performance

Armament

See also

References

Notes
Bibliography
  • Bueschel, Richard M. Mitsubishi Ki-67/Ki-109 Hiryu in Japanese Army Air Force Service. Atglen, PA: Schiffer Publishing, Ltd., 1997. ISBN 0-76430-350-3.
  • Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. London: Putnam and Company Ltd., 1970 (2nd edition 1979). ISBN 0-370-00033-1 (1st edition); ISBN 0-370-30251-6 (2nd edition).
  • Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. Annapolis, MD: Naval Institute Press, 1995.
  • Green, William. Famous Bombers of the Second World War. London: MacDonald & Jane's (Publishers) Ltd., 1975 (2nd Edition). ISBN 0-356-08333-0.
  • Green, William. Warplanes of the Second World War, Volume Three: Fighters. London: Macdonald & Co. (Publishers) Ltd., 1961 (seventh impression 1973). ISBN 0-356-01447-9. (On the Ki-109 Fighter version)
  • "Masterpiece to Manned Missile...Mitsubishi's Final Bomber". Air International, July 1983, Vol. 25 No. 1. pp. 25–33, 47. ISSN 0306-5634.

External links