The Polish pilots were tired with the prolonged training. On August 30, during a training flight, F/O Ludwik Paszkiewicz from 303 squadron saw a group of German bombers. He ignored the order to avoid combat and attacked them on his own, achieving one kill. It was the first shot made by 303 squadron. This made the RAF commanders realise that  the Polish unit achieved full operational capability and detached it on frontline. On the very first day of action – August 31 – six pilots from 303 squadron shot six German aircraft with no loses. On this day RAF incurred the greatest loses in all Battle of Britain. Polish pilots were put to the battle just on time.