Weapons of World War Two
Nakajima B5N2 Kate
The situation of the Japanese Armed Forces on the next day after the Great War was rather confusing regarding the conditions of the armies along which the country had aligned during the conflict. The Navy clearly stood out due to the quality of the ships and the training of the crews. The Army, even having at its side the well known combative spirit of the Japanese soldier, was equipped with materials almost all of them acquired from other nations, specially the most modern ones, factor which certainly had not benefited the development of a specialized national industry, and which tied the country to the game of the weapons supplier nations.
But regarding the aviation there was only an embryo, divided between Navy and Army, and exclusively constituted by imported aircraft. This was not due to the lack of interest towards the new weapon, but to the lack of experience and technological knowledge that Japan, enclosed during centuries on its feudal condition, had not be able to acquire. The few aeronautical companies already existing sent their engineers to specialize in the western universities and industries. When they returned around 1930, the first constructive experiments were started and, finally, they were seen the first results of this effort of renovation. The history of the Second World War would show that these results would be very superior than the most optimistic expectations, specially considering that they were obtained by an industry created in a hurry and from the nothing.
After three years the Japanese Armed Forces would receive the aircraft that would constitute the backbone of their respective aviations, and which would give a lot to do to the Allies. In 1937 would effectuate its first flight the Nakajima B5N (later called "Kate" by the Americans), the aircraft which would sink so many American aircraft carriers and which would be the backbone of the torpedo bomber units. In 1938 would fly the Aichi D3A ("Val"), the best Japanese dive bomber of the conflict, and in 1939 it would be the turn of the Mitsubishi A6M ("Zero"), the fighter which needs no presentation.
Projected the Kate in 1935 by the investigation group led by engineer Katsuji Nakamura, from the Nakajima Hikoki K. K., when it effectuated the test flight in 1937 it widely surpassed the qualities requested in the specification presented by the Navy for an embarked torpedo bomber and, excepting some small modifications, it was immediately accepted. It was a single-engined low-winged monoplane, of entirely metallic construction and with retractable landing gear. The wings were foldable to allow its stowage in the hangar of the aircraft carriers. Its utilization was polyvalent, for it could operate as dive bomber as well.
The engine, initially a Nakajima Hikari 3 of 770 horsepower, would be soon replaced by the Nakajima Sakae 11 of 1000 horsepower, which would give the aircraft a certain increase in speed and would increase its safety factor. During its productive cycle, would leave the production lines 1149 exemplars. The BN5 would be replaced from the late 1943 by the B6N, of better characteristics, but it would continue operating mainly as antisubmarine aircraft, carrying the first Japanese airborne radars on the late 1944, until it was relegated to training service. It seems that some exemplars of the Kate took part in suicide attacks.
First flight: January 1937 (B5N1); spring 1940 (B5N2)
Wingspan: 15.51 meters (about 7 meters with folded wings)
Wing area: 37.70 square meters
Length: 10.30 meters
Height: 3.70 meters
Full load/Empty weight: 3700/2106 kilograms (B5N1); 3800/2280 kilograms (B5N2)
Payload/Crew: 1594 kilograms/3 (B5N1); 1520 kilograms/3 (B5N2)
Engine: Nakajima Hikari 3 of 770 horsepower (B5N1); Nakajima NK 1B Sakae 11 of 1000 horsepower (B5N2)
Time to reach 3000 meters of altitude: 7 minutes 40 seconds (B5N2)
Cruising speed: 260 kilometers/hour (B5N2)
Maximum speed: 370 kilometers/hour (B5N1); 378 kilometers/hour (B5N2)
Service ceiling: 7640 meters (B5N1); 8260 meters (B5N2)
Defensive armament: One orientable 7.7-millimeter machine gun firing rearwards
Drop armament: One 800-kilogram torpedo or 750 kilograms of bombs
Operational range: 2000 kilometers (B5N1); 1800 kilometers (B5N2)
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