The Chu Hummingbird was an experimental co-axial helicopter developed by Chinese aviation engineer Major General C.J. Chu (朱家仁) in China during the 1940s in two versions, designated the Model A and Model B.
Model A was a single seat double rotor test craft used for static (non-flying) test and made its debut in 1945. This model was destroyed when the rotor broke off.
A replacement craft named Model B was introduced in 1948 and was able to fly, but the aircraft was abandoned when Chu left for Formosa.
Not much is known about either model, as they were abandoned in China after 1949 as Chu exiled to Taiwan after the formation of the People's Republic of China.
A successor model, CJC-3 was developed by Chu in Taiwan in the 1950s.