In 1921, the Japanese Naval Arsenal at
Yokosuka started design of a single-engined reconnaissance floatplane to replace the Navy's
Yokosuka Ro-go Ko-gata floatplanes. The resulting aircraft, the
Type 10 Reconnaissance Seaplane, was designed by a team led by a member of a visiting delegation from
Short Brothers of the United Kingdom. It was a single-engined, two-bay, two-seat
biplane powered by a 400 hp (298 kW)
Lorraine-Dietrich engine. Two were completed in 1923 but showed poor performance due to being overweight. A modified aircraft, the Type 10 Model A flew in 1924, showing only slight improvement, while a further revised prototype, the Model B, flew in 1925 - this curing the aircraft's weight problems while demonstrating better stability and control. As a result, several pre-production Type Bs were built. Although the Type 10 was not adopted by the Japanese Navy, In this form, the revised design was accepted in January 1926 as the
Type 14 Reconnaissance Seaplane, later receiving the
short designation E1Y. Two versions entered service in 1926, a two-seater powered by a
Lorraine-Dietrich 1 V-12 engine, the Type 14-1 or E1Y1, and a three-seater with all-metal floats and a more powerful
Lorraine-Dietrich 2 W engine. As the Type 90-3 showed little improvement over the Type 14-2 from which it was developed, in 1931, Yokosuka developed the further refined Type 14-3 Reconnaissance aircraft with a new tail, a geared Lorraine-Dietrich 3 engine, and significantly improved performance. A total of 218 E1Y1 and E1Y2s were built by Yokosuka (23),
Nakajima Aircraft Company (47), and
Aichi (148). 102 E1Y3s were built by Aichi. ==Operational history==