The Aichi H9A was an Imperial Japanese Navy Air Service flying boat used during the first years of World War II for crew training, receiving the designation . An uncommon type, it was not encountered by Allied forces until Spring 1945 and was never assigned an Allied reporting name.
The H9A was a twin-engined, parasol-wing flying boat, designated by Aichi as their AM-21 design. It was designed in response to an Imperial Japanese Navy requirement for an advanced seaplane trainer for future crew members of the four-engined Kawanishi H8K "Emily" flying boat. Design work started in January 1940, and the first of three prototypes was flown in September 1940. The aircraft had a normal crew of five (pilot, co-pilot, observer, flight engineer, and a radio-operator), but seating was provided for an additional three pupil crew members.
From May â June 1942, the Aichi H9A was employed in a variety of second-line roles, including anti-submarine missions along the Japanese coasts, transport, paratroop training, and liaison.