High altitude bombing was not accurate in that era despite the oft repeated claim by the US Army Air Force that a bomber with the top-secret Norden bomb site could drop a bomb into a pickle barrel from 20,000 feet. Maybe on a perfect drop the bomb could get within one hundred yards of the “pickle barrel.” But the aircraft had to be flying on a windless, sunny day in the desert of New Mexico without a sky filled with flak and Luftwaffe fighters.
On active operations in Europe, this proved impossible — a finding the US “bomber barons” refused to accept. And the top-secret Norden bomb-site didn’t work well in poor weather and it wasn’t so top secret, either.
In 1938, a German-American Nazi sympathizer working for Carl Norden, walked out the manufacturing plant with a copy of the plans, which he handed over to the Abwehr, one of Germany’s intelligence services. It was one of the few German intelligence successes against the United States.