"Weight and balance?"
"Fuel transfer, valves and switches?"
"Right, all of them."
"Check, left and right."
"Fuel shut-off switches?"
"Cowl flaps, open right?"
"Open left, and locked."
"De-icers and anti-icers, wing and prop?"
"All set to fire up"
"Command here. All set."
"Master switches on."
"Battery switches and inverters?"
"On and check."
"Booster pumps, pressure?"
"On and check."
"Carburetor coolers open."
"Fuel supply and quantity?"
From A Wing and a Prayer. by Harry H. Crosby.
It is interesting to note here that most bombers of World War II had only one pilot. This was due to a number of factors but most probably it was due to maximizing the manpower the each country had. This is one area where the B-17 was somewhat revolutionary in that it used two pilots instead of one. The main reason for this was the complicated controls associated with a four engined bomber, but there was more to it than that. Just as the designers had built in manual backups for all the hydraulic control systems, so too did they design in a backup in case of human failure (i.e. a pilot being wounded or killed in combat).
This setup also proved to be very helpful during combat as many times it would take the strength of both pilots to handle the aircraft. The additional pilot also helped when the aircraft was in formation. The main pilot couldn't keep an eye on the formation and on his gauges at the same time, so the co-pilot usually looked over the gauges and made sure everything was running the way it was supposed to be while the pilot concentrated on maintaining formation. This arrangement also allowed the pilots to rotate their duties. Flying formation for eight and ten hours on end was, to say the least, strenuous. Many times during the mission, the pilot and co-pilot would swap duties so that not only did the pilot not wear himself out but this also gave the co-pilot some much needed formation flying time and prepared him for the day he would receive his own crew.
Many people believe that the co-pilot was not as good a pilot as the pilot himself, but that is not true. Both pilots received the same training and the only thing that separated the two was chance, which one got picked to be a pilot and which one was picked to be a co-pilot. Granted, some co-pilots got their job due to personal differences, these were the exceptions, not the rule. Co-pilots did receive training in other areas on occasion. Usually this was either navigation or bombardier training. This way, there was a backup crew member trained in navigation or bombing in case one of the crew members responsible for these duties were unable to fulfill them during the mission.
Sometimes the lead aircraft would have its regular pilot replaced by a high ranking officer, such as a Bomb Group, Bomb Wing or even a Bomb Division Commander who would fly in the pilot's seat to observe the mission first hand. In these instances, the regular pilot would fly in the co-pilots' seat and the co-pilot would fly in the tail gunner's position to relay important formation information up to the pilot/co-pilot. The helped the Wing and Group commanders to get a better feel for what the men under their command were up against, what improvements needed to be made to make the bombers more effective and what tactics the Germans were using against the bomber formations. It was after a couple of missions like there when General LeMay came up with his "Defensive Box" formation that dramatically improved a bomb crews chances for completing 25 missions.
Perhaps the most important, and challenging, role of the pilot was that of Crew Commander. The nine other crew members on the Flying Fortress fell under his direct command. The pilot's decisions were final and good pilots always made sure to keep the welfare of their crew as top priority. With bomber crews spending so much time together, the Army's class system of officers and enlisted men broke down and the crew usually acted more like a family with the pilot in the role of father. Thus, the co-pilot often time fell into the role of mother. Many times crew members would default to him with their problems or concerns if they felt their pilot were too busy, didn't care, or unavailable at the moment to listen to them. As such, the co-pilot acted as executive officer to the pilot's role of commander.