Robert Shaw on the general effect of numerical air superiority
In an analysis on the air war during the Winter War in particular and numerical superiority in general, Cdr (USN Ret) Robert L. Shaw (Author of "Fighter Combat") writes: "Quantity is typically much better correlated with the final outcome of a conflict than with aircraft exchange ratios. If the side with superior numbers is willing and able to make good on its losses, it can accomplish its goals in support of the overall effort and eventually achieve victory. The price, however, may be great." See the Fighter Tactics Academy website: http://www.sci.fi/~fta/winter-w.htm
This was precisely the case during the air war over Normandy in the summer of 1944, which cost the Allies many more aircraft than the Luftwaffe lost, but being "the side with superior numbers", and willing and - above all! - able to make good on its losses, the Western Allies could "accomplish their goals in support of the overall effort and eventually achieve victory."
Figures for the air war over Normandy in June 1944
Here are the aircraft loss figures for the air war over France during the period 6 June 1944 - 30 June 1944:
2nd TAF: 322 aircraft (Clark, "Angels Eight", p. 170)
9th AF: 302 aircraft (Rust, "The 9th Air Force in World War II", p. 90)
8th AF: 359 aircraft (137 bombers, 222 fighters) (Freeman, "The Mighty Eighth War Diary", pp. 259 - 283 - only losses in France included)
Total losses by 2nd TAF, 9th AF and 8th AF in France 6 June 1944 - 30 June 1944: 983.
Since losses sustained by ADGB, RAF Bomber Command (which alone lost over 300 bombers in June 1944, many of them over France), and other commands must be added to the figures above, the total number of Allied aircraft lost over France during the period 6 June 1944 - 30 June 1944 definitely exceeds one thousand, I would say approximately 1,200 Allied aircraft were lost over France during this period.
During the same period, the Luftwaffe lost 646 fighters, fighter-bombers and medium bombers in France. (Clark, "Angels Eight", p. 170)
Thus, while almost two Allied aircraft were lost for every German aircraft loss, these losses should be compared with each side's numerical strength. During this period, the Allied air forces performed 99,000 sorties over France (Clark, p. 98 ), while the Luftwaffe only flew 13,315 sorties over France (Prien, "JG 1/11", p. 1051). Thus, the Allied loss rate was only around 1 % while the German loss rate was almost 5 %.
Out of a total of 13,000 Allied aircraft on 6 June 1944, less than 10 % were lost over France between 6 and 30 June 1944. Out of 1,300 Luftwaffe aircraft in France (the peak number, reached on 10 June), around 50 % were lost between 6 and 30 June 1944.
Part 4, the last part of this article, examines the cases when a number of German aces were killed in action during the Battle of France in 1944