Immediately after the declaration of war, Hermann Sommerfeld enlisted with the German Air Force which had been established in 1910.  He was considered an able army pilot, who, while training as a pilot in Schneidemühl, went on 14 flights per day. When he was about to land after his 14th flight, he crashed into plane of a comrade, who had put his machine in his way recklessly and against all regulations as a demonstration of his anti-Semitic sentiments. Sommerfeld sustained a severe concussion in this incident, but immediately after his recovery, he went to the Frescati Airport and flew 100 sorties to the front. According to the log book, he also flew sorties for the infantry with observers, photographers, gunners, etc.

He was finally stationed behind the front as the result of the base anti-Semitic machinations of a superior. As a Jew he was doomed to watch helplessly as he was transferred into the aircraft maintenance unit and be counted in the statistics as a soldier behind the front.