 The new anti @-@ aircraft communication links allowed areas threatened by German bombardment to be warned , German artillery spotting aircraft to be attacked and German artillery batteries to be fired on when they revealed themselves . From 1 – 7 June , II Brigade had 47 calls through wireless interception , shot down one German aircraft , damaged seven and stopped 22 German artillery bombardments . Normal offensive patrols continued beyond the barrage line out to a line from Ypres to Roulers and Menin , where large formations of British and German aircraft clashed in long dogfights , once German air reinforcements began operating in the area . Longer @-@ range bombing and reconnaissance flights concentrated on German @-@ occupied airfields and railway stations and the night bombing specialists of No. 100 Squadron RFC attacked trains around Lille , Courtrai , Roulers and Comines . Two squadrons were reserved for close air support on the battlefield and low attacks on German airfields . 
