Several generations of Japanese naval aircraft fought over China, giving the navy continuing evidence of whether its equipment met operational needs. The A4N improved on the A2N, while the B3Y exposed serious weaknesses in the navy's own aircraft and engine development. Introduced in 1933, the B3Y had already shown poor stability, weak control and an unreliable engine during testing. Competing Mitsubishi and Nakajima designs were less successful, so the navy accepted its arsenal's design and sought outside help with the defects. Its Hiro Type 91 water-cooled engine required extensive remedial work and became only partly reliable before replacement. The contrast with the dependable engine development behind the A2N and A4N shows how uneven Japan's results could be.
Chapter · 46:22-51:17
The B3Y exposes uneven results in Japanese aircraft and engine development
China provides continuing operational feedback, while the B3Y's earlier testing and unreliable Hiro engine illustrate the failures within Japan's own design programs.