The prototypes were accompanied by Heinkel test pilot Gerhard Nitschke, who worked with Lieutenant Mitsugi Kofukuda during the tesing and evaluation. The Navy was so impressed by tests that they planned to put the aircraft into production as soon as possible, as their land-based interceptor. (Unlike every other armed forces organization in the world, the Japanese Army and Navy both fielded complete land-based air forces.) Hitachi won the contract for the aircraft and started construction of a factory in Chiba for its production. With the European war on, the jigs and plans never arrived.