 On 1 April, he was promoted to "Unteroffizier" (non-commissioned officer).In May 1942, I./JG 53 was transferred to the Eastern Front near Kursk.Crinius achieved his first victories on 9 June when he shot down two Il-2 "Sturmovik"s. On 8 July, Crinius shot down two Douglas Boston bombers west of Voronezh, although his aircraft was hit by Russian anti-aircraft fire and he was forced to belly-landed his Messerschmitt Bf 109 F-4 ("Werknummer" 10243—factory number) between the enemy lines, where he was rescued by a German patrol and safely returned to his unit.