The Bücker Bü 131 Jungmann was produced under license in Spain, Switzerland, Hungary and Japan, as well as by the Czechoslovak company Tatra. During the Nazi occupation, production was entrusted to the Aero factory and continued even after the end of WWII under the designation C-4. The installation of the Czechoslovak Walter Minor 4-III engine created a version known later as the C-104. By 1949, 260 of these machines had been produced in Czechoslovakia with this example on display at the Letecké Muzeum Kbely.

[Olympus PEN E-PL2 + M.Zuico 14-42mm]