The Focke-Wulf Fw 159 was an experimental German fighter of the 1930s that never reached production. The Focke-Wulf company designed the aircraft as one of the four entries for the Rüstungsflugzeug IV ("Armed Aircraft IV") 1934 fighter competition. Its parasol wing configuration was based on the company's successful trainer product, the Focke-Wulf Fw 56 Stösser and it used a Junkers Jumo 210 engine. The plane had a rearwards-retracting. lever action suspension main undercarriage, retracting completely into the lower fuselage, and an enclosed cockpit, although the main undercarriage mechanism was very complicated, fragile and proved endlessly troublesome.