5 decal variants:
1. Bücker 131D, RAF, Special Duties Flight at Christchurch, England 1941
2. Bücker 131D, Japan 1945
3. Bücker 131D, Poznan Flying Club, Poland 1948
4. Bücker 131D, Regia Aeronautica, Tiranna 1941
5. Bücker 131D, RYAF, Pancevo, Yugoslavia 1940
During 1936, was produced Bü 131B with powerful 105hp Hirth HM 504A-2 engine. Most produced was the version D. The aircraft was used by Luftwaffe as training, also by night ground-attack. Was also exported in many countries - Japan, Switzerland, Spain, Yugoslavia, Romania and Bulgaria. Under licence was built in Japan and after WWII also in Spain-CASA and Czechoslovakia as C-104 trainer with Walter Minor 4-III.