The Messerschmitt Bf 109 was a World War II fighter aircraft designed by Willy Messerschmitt in the early 1930s. It was the first true modern fighter of the era, including such features as an all-metal monocoque construction, a closed canopy, and retractable landing gear. The Bf 109 was the standard fighter of the Luftwaffe for the duration of WWII, although it began to be partially replaced by the Focke-Wulf Fw 190 from 1942. The Bf 109 scored more aircraft kills in World War Two than any other aircraft in history, and at various times served as an air superiority fighter, an escort fighter, an interceptor, a ground-attack aircraft and a reconnaissance aircraft. The Bf 109 was produced in greater quantities than any other fighter aircraft in history, with over 31,000 units built. Although the Bf 109 had a few weaknesses, including a short range of around 360 miles (580 km) in all versions, and sometimes difficult to handle narrow track, outward-retracting main landing gear, it stayed competitive with Allied fighter aircraft until the end of the war.