Why did the Aichi H9A never get an Allied codename?

Short answer

Because the Allies barely saw it: the Aichi H9A was a relatively uncommon type and they did not encounter it until the spring of 1945, so it was never given an Allied code name. It was a twin-engine training flying boat: of the production version, Aichi built 24 aircraft and Nippon Hikoki another four.

Published: November 1, 2026 · Updated: November 1, 2026 · Edited by Above Ten Thousand · Editorial policy

Why did the Aichi H9A never get an Allied codename?

North American Rockwell Shrike Commander 500S, Robert A. "Bob" Hoover

A flying boat for training crews

The H9A was developed in response to an Imperial Japanese Navy instruction to Aichi to provide a twin-engine flying boat configured for training the future crews of the four-engine Kawanishi H8K "Emily" maritime patrol flying boat. It was a parasol-wing, twin-engine flying boat designed to meet that crew-training requirement. Its design crew was five men — pilot, co-pilot, observer, flight engineer and radio operator — with enough seats for three trainees to travel as well.

Few built, no code name

Of the production version, apart from the prototypes, Aichi built 24 aircraft and Nippon Hikoki another four. The first eleven were delivered to the Imperial Japanese Navy during 1942. As it was a relatively uncommon type, Allied forces did not encounter it until the spring of 1945 and never assigned it a code name.

Second-line duties

Between May and June 1942, Japanese naval aviation used its H9As in a variety of second-line roles: anti-submarine missions along the Japanese coast, transport, paratrooper training and liaison. The prototypes had two-blade propellers, whereas the production aircraft were distinguished by three-blade propellers.