British Blenheim Bombers here sweep over the flat Dutch fields low enough to wave to the enslaved Dutch farmers. While most of the German Luftwaffe is busy in the U.S.S.R., they may be said to have relative air superiority. But they are not flying low just to be chummy with the Dutch. Against low-flying planes, the German fighters cannot dive for fear of running into the ground, ground spotters get minimum warning; anti-aircraft guns cannot take aim. The date of this sweep was July 16.