 By the end of the first week , the Luftwaffe had achieved air supremacy over the battlefields of all the army groups , but was unable to effect this air dominance over the vast expanse of the western Soviet Union . According to the war diaries of the German High Command , the Luftwaffe by 5 July had lost 491 aircraft with 316 more damaged , leaving it with only about 70 percent of the strength it had at the start of the invasion . 
