The Imperial Japanese Navy commissioned the G3M "Nell" medium bomber in 1935. At the same time and, not to be outdone, the Imperial Japanese Army commissioned the Ki-21 heavy bomber. The Ki-21 was much faster than the Navy's G3M and carried a larger payload as well. It was used during effectively in the years leading up to WWII, but was extremely vunerable to enemy fighters. So the Ki-21 was revised to include larger control surfaces, rudimentary self-sealing fuel tanks, and a couple more machine guns. This version, known as the Ki-21-IIa (shown below) was used during the first year of WWII where it faced meager assault from the Brewster F2A Buffalo. However, once it began to encounter the Curtiss P-40 Warhawk, Mitsubishi had to tweak the design again including the replacement of the dorsal observation canopy (because, you know, sight-seeing) with a rotating gun turret. The final version (Ki-21-IIb) only remained in service through 1942 before most were sent retrofitted as transports or sent back to Japan for training purposes. A total of 2,064 Ki-21 aircraft were built by Mitsubishi (1,713) and under license by Nakajima (351).
 

 Class: Medium Bomber

 Crew: 7

 Engine: 2 x Mitsubishi Ha-101 14-cylinder twin-row radial (1,500 hp each)

 Max Speed: 302 mph at 19,685 ft

 Climb Rate:  1,485 ft/min

 Service Ceiling: 32,810 ft

 Range: 1,678 miles

  Model Scale:  1:120