Bücker Bü 133

The Bücker Bü 133 Jungmeister (German for “young champion”) was a single-engine, single-seat biplane designed for advanced training and aerobatics, developed and produced in the 1930s. The Bü 133 was designed to provide an effective aircraft for training pilots in the flight schools of the newly founded Luftwaffe. It was then purchased by several foreign countries, such as the Kingdom of Yugoslavia and Switzerland. It was later sold to countries allied to the Tripartite Pact and to Spain, which also built it under licence for the newly formed Ejército del Aire. Source: Wikipedia