Big surprise to most of the world in the Nazi drive through the Lowlands and northern France was the terrible accuracy of German dive bombers. Except for the U. S. Naval Air Service (which originated dive bombing, still works hard and ably at it), few of the world's air forces had fully realized the sharpshooting possibilities of a heavy bomb projected straight & true from a diving airplane.
Last fortnight across the Atlantic came details of another brand of German attack from the air: high-altitude, level-flight bombing, which the U. S. Army Air Corps uses to the exclusion of the diving attack. Returning travelers who saw the daylight raid on Paris, hundreds of other attacks through France, told of hearing raiders so high that they were out of sight in the clear sky. Yet these planes, starting out their campaign by smashing up France's airfields and pursuit resistance, methodically and unspectacularly brought a creeping paralysis to France's communications. Road junctions were reduced to craters, railroad junctions and yards were smashed and littered with wreckage. Military headquarters were knocked out by sharpshooting bombers almost as soon as they were set up. Apparently few bombs were wasted by bad shooting. Harold Francis McEnness, European representative for big, research-wise Bendix Aviation Corp. (aircraft carburetors, magnetos, instruments, other accessories), told of a raid on the Citroen automobile plant outside Paris.
"There were about 250 planes in the attack," said he. "They were so high you couldn't see them but their number was estimated by the number of bombs dropped. Their accuracy was terrific. Of all the bombs dropped . . . the majority plunked right into the factory."
Quick was Harold McEnness to surmise that the Germans either had learned the secret of the closely guarded U. S. bombsight, or had developed one of their own. Quick were Army Air Corps officers to say that the U. S. sight was still a U. S. secret. But none doubted that German ingenuity had developed a bombing sight for World War II that was modern, scientific, accurate. Typical level-flight bomber in the medium range (24,900 Ib. fully loaded) is the sleek, two-engined Heinkel He. in K which carries a crew of four, makes bombing a highly coordinated job for two men, the pilot and the bombardier. These, with other types (Dornier, Junkers, etc.), were the ships that were trying to soften up Britain with intensified raids all last week (see above). A Heinkel He. in K is pictured on the opposite page during a hypothetical attack on the vital Thames Estuary and London docks.
The advantage of level-flight bombing from high altitude is that it keeps bombers out of effective range of anti-aircraft batteries, forces defending pursuit to climb higher and farther to give battle. Its only limitation in good weather is the accuracy of the bombsight.