Mitsubishi Ki-67
The Mitsubishi Ki-67 "Hiryū" (飛龍, "Flying Dragon"; Allied reporting name "Peggy") was a twin-engine heavy bomber produced by Mitsubishi Heavy Industries and used by the Imperial Japanese Army Air Service and Imperial Japanese Navy Air Service in World War II. Its Army long designation was "Army Type 4 Heavy Bomber" (四式重爆撃機). Japanese Navy variants included the P2M and Q2M. Design. The Ki-67 was the result of a 1941 Japanese army specification for a successor to the Nakajima Ki-49 "storm dragon". 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. The Ki-67 was designed by a team led by Kyūnojō Ozawa, 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, features common in US fighters and bombers but  frequently lacking in Japanese aircraft. With these features and its two 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 North American B-25 Mitchell could carry up to 2,722 kg (6,000 lb), the Martin B-26 Marauder up to 1,814 kg (4,000 lb), and the Douglas A-20 Havoc up to 907 kg (2,000 lb), for example, but they rarely  carried a maximum load; when they did, their range was reduced significantly. Japanese aircraft almost invariably had greater range with their rated maximum load; this gave them a strategic capability unlike that of Allied twin-engine bombers, which were considered tactical bombers. The Ki-67's performance was remarkable compared to US medium bombers; the Ki-67 had a level-flight top speed of - against for the B-25, 462 km/h (287 mph) for the B-26, and 538 km/h (338 mph) for the A-20 -, good manoeuvrability in high-speed dives (up to 644 km/h/400 mph), excellent sustained rate of climb , and outstanding agility (excellent turn rate, small turn radius, and ability to turn at low speeds). The manoeuvrability of the Ki-67 was so good that the Japanese used the design as the basis for the Mitsubishi 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 Mitsubishi Q2M1 ""Taiyo"" radar-equipped anti-submarine aircraft. Armament of the Ki-67 included a dorsal turret with a 20 mm (.79 in) Ho-5 cannon, in  addition to 12.7 mm (.50 in) Ho-103 machine guns in the tail, nose, and beam positions. Some aircraft were fitted with a 20 mm gun in the tail position, and early models used 7.7 mm (.303in) Type 89 machine guns in the beam positions. Operations. The Ki-67 was used for level bombing and 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 and Tinian. 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) Type 3 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-Gō" 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.