 In 1940 Johnson had an operation to reset his collarbone , and began flying regularly . He took part in the offensive sweeps over German @-@ occupied Europe from 1941 to 1944 , almost without rest . Johnson was involved in heavy aerial fighting during this period . His combat tour included participation in the Dieppe Raid , Combined Bomber Offensive , Battle of Normandy , Operation Market Garden , the Battle of the Bulge and the Western Allied invasion of Germany . Johnson progressed to the rank of group captain by the end of the war . 
