In May 1940 Losigkeit was in command of 2./JG 26 based at Audembert on the Channel Coast. Piloting the Me109 he flew over 100 missions during the Battle of Britain and, like the RAF pilots he flew against, often flying up to five missions per day.

Five years later, after 750 operational missions in both the East and Western theatres, in 1945 Fritz Losigkeit was still in action. Now in command of JG 77 in Czechoslovakia, he was detailed to form a special unit from all available aircraft types for ground attack operations against the advancing allied armies. Concurrently JG 77 took part in fighter interceptions of bomber forces defended by powerful forces of long-range fighters. Losigkeit recalls the aerial battles were ferocious.