Originally Posted by
eggplantwalking
The timeline makes the difference. The 303 Bomb Group manual was dated 1943. Flight engineer training formally started in Texas for enlisted personnel in March of 1944 and during that interval a lot changed.
No, the early B-17s sent to the Philippines had FEs as did MG Caleb Haynes crop of B-17s in Task Force Aquila - that was pre-Doolittle in 1942. Scott (in his book God is My Co-Pilot pg. 39) references his engineer (and gunner in case of attack), Sgt.Aaltonen, standing behind the flight deck.