The IJN had watched the development of British and American dive-bombers during the interwar period with some interest. Determined to procure their own aircraft of this type, the navy approached the Aichi aircraft company, who would go on to produce a series of successful ‘carrier bombers’ as they were called in IJN parlance. The D1A was originally a German design, as Aichi approached Ernst Heinkel for his assistance. Heinkel produced the He66 which was provided to Aichi, and in 1934 became the basis for the D1A.

The D1A was, like most small aircraft of the time, a biplane. Of metal construction with fabric covered wings and fuselage, it was initially powered by a Nakajima Kotobuki 2 which produced 490hp, but this was soon replaced by the more powerful Kotobuki 3. The D1A1 was accepted into service as the Type 94 Carrier Bomber, with the updated D1A2 (sometimes called the D2A) receiving the designation Type 96 Carrier Bomber.

Type 94/96s had a successful early career, flying from aircraft carriers and land bases during the early part of the Sino-Japanese War. They proved extremely effective in the dive-bombing role, playing a major part in the sinking of Chinese warships on the Yangtze and Pearl rivers in 1937. They also provided support to Japanese troops advancing on Shanghai, Nanking and Hankow, fully validating the dive-bomber concept.

By the time the wider Pacific War had started, Type 94s had been withdrawn from service and Type 96s were restricted to second line and training duties. The type was assigned the Allied reporting name “Susie” in 1942.