 Complete the following phrase:  Ebener began a military career, joining the Luftwaffe on 17 November 1939. He was posted to 4 JG 3 based on the Eastern Front. On 23 May 1942 he scored his first two victories when he shot down two Russian Polikarpov I-16 fighters. Ebener reached his 10th victory on 30 July and his 20th on 17 December. From December until January 1943 he operated from within the 