Production of the P.Z.L.11a (left) began in 1933, with thirty machines being delivered to the Polish Air Force in 1934. These were powered by a 500 hp Skoda-Mercury IV-S2 engine and carried an armament of two 7.7 mm Browning Mk.33 machine guns with 700 r.p.g.
By 1939 most of the P.11a fighters had been relegated to the training schools, although several machines actually saw combat during the German invasion .
