 He claimed a half-share in damaging a German Messerschmitt Bf 109 on the first day of the war, while flying a PZL P.11c.Over the next week he was reported to have shot down two Dorniers Do 17 bombers, damaging two more.On 14 September he was assigned a courier mission, delivering messages to General Juliusz Rómmel, and Marshal Edward Rydz-Śmigły, flying into the encircled pocket at Młynów.