Takeo Doi (aircraft designer)

Takeo Doi (土井武夫, Doi Takeo^?, 31 October 1904 – 24 December 1996) was a Japanese 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". Also he was one of the chief designers of the Nihon Aircraft Manufacturing Corporation (NAMC) YS-11.

Takeo Doi was born in Yamagata city, Yamagata prefecture, Japan in 1904. He graduated from the Yamagata Higher School in 1924, and Department of Aeronautics, Faculty of Engineering, Tokyo Imperial University in 1927 . Jiro Horikoshi and Hidemasa Kimura, who designed the Mitsubishi A6M Zero fighter and the Koken (Tokyo Imperial University Aeronautical Research Institute) Long-range Research-plane, respectively, were his classmates at the department in the university.