I've found mentions that in some air forces, like the Luftwaffe and perhaps the French Air Force, bombers were commanded not by their pilots, but by another crewmember (bomb aimer maybe), that was the highest ranking officer on board (or the only officer,as the Luftwaffe had many enlisted pilots), and was trained to fly the plane, navigate it, and basically do the job of each crew member.
Do you guys know anything of this? Any websites dealing with the matter?