As highlighted in Martin W. Bowman’s classic work, Castles in the Air , the B-17 became the "main punch" for the during its daylight bombing offensive over Nazi Germany. Unlike the British Royal Air Force (RAF), which eventually shifted to night bombing, the Americans believed the B-17’s heavy defensive armament and the secret Norden bombsight allowed for high-altitude, precision daylight strikes.
The B-17’s journey began with a near-catastrophic failure. The prototype, known as , first took flight in July 1935. Despite outperforming its competitors in speed and range, the prototype crashed during a demonstration, nearly ending the program before it began. However, the U.S. Army Air Corps saw enough potential in the "15-ton flying fortress"—a name coined by a Seattle Times reporter—to order 13 more for testing. The Hammer of the Eighth Air Force Castles in the Air - the Story of the B-17 Flyi...
: By the time the definitive B-17G model appeared, it boasted 13 .50-caliber machine guns, including a "chin turret" to counter head-on attacks. Beyond the Bombing Run As highlighted in Martin W