 Complete the following phrase:  At the beginning of World War II in September 1939, Helbig held the rank of Second Lieutet and was serving as an observer in a He 111 reconnaissance aircraft of Demonstration Wing 1 Lehrgeschwader 1 II.LG 1 in 1938. He was awarded the Iron Cross 2nd Class following the campaign. Helbig took part in the April 1940 invasion of Norway 