The PZL P.11 was a Polish fighter aircraft, designed in the early 1930s by PZL in Warsaw. It was briefly considered to be the most advanced fighter aircraft design in the world. The PZL P.11 served as Poland's primary fighter defence in the Polish campaign of 1939. The final variant for the Polish air force, the P.11c had a new, refined fuselage, with the engine lowered in the nose to give the pilot a better view. The central part of the wings was also modified.