Centralne Studium Samolotów, aeroplane research centre, established 1946 to develop primary trainer, aerobatic trainer and light transport. First, CSS.10A, flown 3 September 1948; 2nd, CSS.10C, flown 25 April 1949; followed by 2 versions of more powerful CSS.11. Transport CSS.12 (2 x 440-hp Argus) flown 22 November 1950. CSS eliminated in political changes.