A belly turret was also added. Positions in the side also had machine guns installed.
The tail of the B-17E was made larger to provide better stability. This also allowed for a rear machine gun to be installed for defense.
In early 1942 the B-17E was sent to units in the Pacific.
In July 1942 the B-17E was delivered to units in Europe. On August 17, 1942, they conducted their first raid against Rouen.