After designing the P.7, Puławski started further variants with larger engines, eventually cumulating in the P.11. During August 1931, the first P.11/I prototype conducted its maiden flight, powered by the British Bristol Jupiter radial engine; the first flight had occurred shortly after Puławski's death in an air crash. It was followed by a pair of refined prototypes, the P.11/II and the P.11/III, which used the Bristol Mercury engine instead. They were later joined by several more pre-production aircraft to test out various configurations of engines, propellers, and other features; these test examples led to the P.11/VI, a production-representative version of the design.