Takeo Doi (aircraft designer)

He designed many World War II fighter aircraft used by the Imperial Japanese Army Air Force.

His most important work was the "Army Type 3 Fighter" (三式戦闘機, Sanshiki sentoki), aka Kawasaki Ki-61 "Hien" (飛燕, Hi-en) ("flying swallow") or "Tony".

He graduated from the Yamagata Higher School in 1924, and from the Department of Aeronautics, Faculty of Engineering, Tokyo Imperial University in 1927[1] .

The company invited Vogt from Germany as a technical advisor to teach its engineers in the construction techniques of Dornier aircraft which Kawasaki was building under license.

After Vogt returned to Germany, Doi became the key person in the design bureau of Kawasaki Aircraft until the company ceased operations at the end of World War II.

When the treaty lifted the ban on designing and operating aircraft, Doi returned to his original work.

In 1956 the Ministry of International Trade and Industry of Japan announced a domestic production plan of middle-sized commercial aircraft, i.e. the YS-11.

A Kawasaki Ki-100 on display in the RAF Museum at Hendon
Kawasaki Ki-45 " Toryu ". Doi designed not only the single-engine aircraft but also multi-engine ones.
NAMC YS-11 operated by Japan Air Commuter (JAC). YS-11 is the only successful commercial aircraft made by Japanese manufacture. Doi joined the project as a chief designer in charge of aeronautical equipment.