the Air War on D-Day
Nazi air power was on the ropes. By March 1944, 56 percent of Nazi fighter fleet was lost, dropping to 43 percent in April as the Allied bomber effort switched to Germany's petroleum production, and rising again to just over 50 percent in May, prior to the Normandy invasion.
However, the Luftwaffe did contribute about a hundred sorties to the defense of Normandy. The available Nazi fighters fought viciously.
To understand air combat, to disable an aircraft takes only a couple of projectiles. When an aircraft is hit with the full brunt of heavy machine gun or cannon, it often explodes.
As depicted on the left, only four rounds of 13mm strike Tom's P-38: two rounds going into the left engine - setting it afire, and two rounds striking the armor plate.
Fire in an aircraft is not a good thing and disabled aircraft cannot fight well.
Had a steady stream of 13mm (.50 caliber) smacked the left engine pod & boom, the wing would have come free and Tom's plane would have snap-rolled left, out of control.
Also, as the wing tore free the left fuel tank would have ruptured and the aircraft would have probably exploded.
The incident described in the story took only less than a couple of minutes.