Boeing B-17 Flying Fortress B-17E

The B-17E (299O) was an extensive redesign of the B-17D: the most visible change was the much larger, all-new vertical stabilizer (inherited from the Boeing 307 Stratoliner), which came together with a new tail-gunner position and a powered dorsal turret behind the cockpit, each carrying a pair of .50-cal Brownings. Until then the bomber had to be yawed in flight so waist gunners could cover the tail. The first production run fitted a remote-sighted Bendix ventral turret that proved a combat failure and was replaced by the manned Sperry ball turret on the rest of production. 512 were built against the USAAC's July 1940 order.