Helnkel HD 23 carrier fighter
In 1926, Aichi contracted Heinkel to design a carrier fighter for entry into a Navy competition to replace the Mitsubishi Type 10 fighter then in service. Called the HD 23 by Heinkel, it was known as the Aichi Type-H Carrier Fighter in Japan. Two were built by 1927 and much emphasis was placed on the capability of the plane to ditch at sea, including jettison – able landing gear and the ability for the engine to stop the propeller in the horizontal position. However, performance-wise, the Aichi Type-H Carrier Fighter showed up poorly and lost the competition to Nakajima.
Heinkel HD 25 two-seat float plane
Licence-built in Japan as the Aichi Navy Type 2, this aircraft saw service on a number of heavy cruisers from 1926 onwards, though their service life was short due to the advent of catapult launched seaplanes. The few Aichi Navy Type 2 aircraft were then sold to the civilian market. Later, in 1930, three Type 2 aircraft were converted to transports for civilian use.
Heinkel HD 25 transport
Built as the AB-1, Aichi used the Heinkel HD 25 as the basis for their entry into a ‘made in Japan’ passenger/transport contest operated by the Aviation Bureau of the Department of Communications. The AB-1 could be converted to a seaplane if required and proved its worth going on to win the contest and seeing several years’ service in private hands.
Heinkel HD 26 single-seat float plane
A single example was built by Aichi (also as the Aichi Navy Type 2) while the Navy also acquired a Heinkel constructed HD 26. Both were tested in 1926, but like the two-seater, the model was made obsolete by catapults. Both aircraft were turned over for civilian use.
Heinkel HD 28 three-seat float plane
The Navy purchased one HD 28 from Heinkel in 1926. Tested by the Navy, problems with the Lorraine-Dietrich engine saw the HD 28 failing to meet expectations and in 1928 the Navy withdrew their interest in the design.
Heinkel HD 56 seaplane
To meet a 1929 Navy need for a catapult launched seaplane, Aichi once more turned to Heinkel and imported the HD 56. Meeting the needs of the Navy after modification, it was accepted into service in 1931 as the Aichi E3A1 beginning with the first deliveries out of an eventual total of 12 aircraft. The E3A1 saw combat during the Sino-Japanese conflict, operating from Jintsu-class cruisers. It did not, however, remain in service long, being replaced with superior aircraft. Some E3A1 seaplanes were retained by the Navy as trainers with the remainder released to the civilian market.