The Nakajima B5N was designed to a 1935 requirement. The design team was headed by Katsuji Nakamura. The aircraft had to have a wingspan less than 54' and be able to be folded to 24'. It was to carry a 1,760 lb torpedo. Other requirements were that it had to be able to cruise between four and seven hours, fly at 210 mph at 6,500'.
The wings were foldable for storage on a carrier.
Unusual for a plane, much less a carrier plane, at the time, the B5N had an inward retracting landing gear.
The fuselage was all metal stressed skin.
The engine drove a variable pitch propeller.
1941 Torpedo Bomber Comparison