Allied fighter-bombers

Allied fighter-bombers continued to attack not only front-line positions, but also any supply trucks coming up behind with food, ammunition and fuel. The almost total absence of the Luftwaffe to contest the enemy's air supremacy continued to provoke anger among German troops, although they often resorted to black humour. 'If you can see silver aircraft, they are American,' went one joke. 'If you can see khaki planes, they are British, and if you can't see any planes, then they're German.' The other version of this went, 'If British planes appear, we duck. If American planes come over, everyone ducks. And if the Luftwaffe appears, nobody ducks.'

D-Day, by Antony Beevor