 During one of these missions, strafing the railway up the Vardar valley and an airfield near Niš, Ihlefeld was shot down in his Bf 109 E-7 ("Werknummer" 2057—factory number) by anti-aircraft artillery and was captured by Yugoslavian soldiers.The airfield at Niš was practically deserted and Ihlefeld had been hit by small arms fire and was slightly wounded in the head.While in their custody, he was allegedly severely beaten, and threatened with execution by firing squad.