At the beginning of World War II in September 1939, Helbig held the rank of Second Lieutenant 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 (Operation Weserübung). As part of II. "Gruppe", he flew missions in support of the German ground forces, particularly in the Åndalsnes area. During one of these missions on 2 May, his unit sank the Norwegian hospital ship with heavy losses. Following their attack on "Dronning Maud", the German aircraft then bombed the nearby village of Gratangen, destroying several houses and killing two civilians. Shortly afterwards, the unit returned to Germany. During the Battle of France later that month, Helbig served as squadron commander of the Fourth Squadron of LG 1, flying both He 111 and Junkers Ju 88 bombers, a position he held until 5 November 1941. While attacking shipping during the Battle of Dunkirk on 1 June, Helbig's Ju 88 was intercepted by Supermarine Spitfires of No. 616 Squadron RAF. They damaged the aircraft, and lightly wounded Helbig, but he was able to return to base. For his actions, he was awarded the Iron Cross 1st Class.