Could the Army Air Forces have developed a B-17 variant for long-range maritime patrol?
Short answerYes, it was possible, but the Army did not field such an aircraft for this role.
NotesAdapting the B-17 into a long-range patrol aircraft was technically possible. The decisive limitation was institutional and historical rather than aerodynamic: the Army did not create and deploy that variant for this task. A capability that could be developed is different from a reconnaissance force that was funded and positioned. The patrol gap existed because the proposed aircraft was never fielded for the role.