Bücker Bü 131 Jungmann Bü 131A

The Bü 131A is the configuration in which the Jungmann was born. The prototype, registered D-3150, made its maiden flight on 27 April 1934 with Joachim von Köppen at the controls, barely two years after Carl Clemens Bücker had founded the company at Berlin-Johannisthal with the young Swedish engineer Anders J. Andersson leading the design. Deliveries began that same year, making the Bü 131 the first aircraft of the firm to attain production status; it would also be the last biplane manufactured in quantity in Germany.

The A series was powered by the Hirth HM 60R, an 80 hp four-cylinder inverted air-cooled inline engine. With it, according to the 1983 Air Britain Digest, the aircraft took seven minutes to reach 1,000 metres, a figure the B version would cut to just over five. The first examples were delivered in 1934 to the Deutscher Luftsportverband (DLV), the sporting organisation that concealed pilot training before the Luftwaffe was officially created. The production record quoted by the German Wikipedia attributes 223 aircraft with the HM 60 engine, i.e. the A series, to Reich Air Ministry (RLM) orders, against 1,356 with the HM 504 of the B and D series.

The A also reached export customers in small numbers: the Air Britain Digest cites, for instance, Count Festetich's aircraft in Hungary as a Bü 131A, and the Fundación Infante de Orleans recalls that some of the 95 Jungmann delivered to Spain during the civil war carried the 80 hp Hirth, although most already had the 105 hp engine. Its replacement was swift: in 1936 production switched to the B version with the more powerful engine.