This video clip
http://search.eb.com/normandy/video/onormay151v1.mov
shows German 2, 3.7 and 8.8 cm flak desperately trying to hack Anglo Typhoon jabos out of the Normandy sky.

Eventually they get one, but it shows their difficulty. One shot shows an aircraft bracketed by two accurate fuzed explosions, but it sails straight on through.

Aiming directly without fuzes or having proximity-fuzed rounds would have worked wonders for the flaktruppen's score.