The Mitsubishi Ki-21, formal designation " Type 97 Heavy Bomber " (九七式重爆撃機, Kyūnana-shiki jūbakugekiki) was a Japanese heavy bomber during World War II.

The Mitsubishi G3M (九六式陸上攻撃機, Kyūroku-shiki rikujō kōgeki-ki, as Type 96 land-based attack aircraft "Rikko"; Allied reporting name "Nell") was a Japanese bomber and transport aircraft used by the Imperial Japanese Navy Air Service (IJNAS) during World War II.

Designed and built by Mitsubishi. The Japanese Army Air Force (JAAF) Type 97 Heavy Bomber / Ki-21 was the main long range Army bomber in service at the start of the Pacific War. This bomber was a contemporary of the Mitsubishi Type 96 / G3M Nell. Allied code name "Sally".

May 19, 2015 · Fitted with Nakajima Ha-5 engines, the aircraft was capable of over 250mph, as the design contract required. Later models were capable of carrying a 1,000kg bombload, twice as much as the Navy’s equivalent G3M.

The Mitsubishi Ki-21 was certainly not as famous as the G3M and G4M bombers, but it was the "draft horse" of the Japanese army air force did much to put the army air force on a par with that of the navy. The first prototype took to the air on December 18, 1936, with production on the first version beginning in November, 1937.

The first prototype Ki-21 flew on December 18, 1936. The Ki-21 was a midwing plane with X-6 Kinsei (Gold Star) engines with Hamilton Standard three-blade variable pitch propellers.

The Mitsubishi Ki-21, formal designation"Type 97 Heavy Bomber" (九七式重爆撃機,Kyūnana-shiki jūbakugekiki) was a Japanese heavy bomber during the Second WorldWar.

one trainable in the dorsal turret and one trainable rearward-firing in the ventral position. Bomb load: 1,100 - 2,205 lb of bombs. First production model. The development of the Mitsubishi Ki-21 aircraft begins in 1936 when new specifications for the bomber were issued.

It was to have a top speed of 400 km/h (250 mph), endurance of at least five hours, and a bomb load of 750 kg (1,650 lb). Both Mitsubishi and Nakajima were asked to build two prototypes each.

2 x Mitsubishi Ha-101 air-cooled radial piston engines, 1,500 hp each driving three-bladed propeller units. 1 x 12.7mm Type 1 machine gun in the dorsal turret. 1 x 7.7mm Type 89 machine gun in nose. 1 x 7.7mm Type 89 machine gun in stern gun position. 1 x 7.7mm Type 89 machine gun at the ventral gun station.