Bombing Mission
It's not long before the ordnace crew arrive with the bomb loads. The service truck is pushed under the plane and located below the bomb bay. The trailer contains ten M-43 500lb general purpose bombs. They are all marked with two yellow bands front and back; the indication that they contain TNT. The ordnance crew attach the shackles from the B-17's racks to two lugs on each bomb. The bombs are then winched into the bay an placed at the correct station. The tail fins are screwed on and the nose and tail fuses carefully fitted into the bomb. Each fuse has a small propeller.like vane securing wire that will be removed by a member of the crew after the bomber hat taken of.
Meanwhile, the ground crew are pre-flighting the B-17. The prop blades are pulled and turned through three complete revolutions, to remove any excess fuel which may have seeped down overnight. The Chief performs his checks. He turns on the battery and ignition switches and ensures that the terminals on the voltage converters are not shorting. The fuel booster pump is turned on, the pressure checked and the throttle set to 1000 rmp. He starts number one engine, then the other three. The turbo supercharging system, that enables the 1,200hp engines to run at full power between 20,000 and 30,000 feet, is inspected and the prop pitch controls are checked. Then everything reported faulty from the previous day's mission is checked again.
At the same time an ammunition truck appears and unloads 10 wooden boxes of 0.50 calibre ammo into the rear fuselage door. The 0.50 calibre machine guns are loaded onto the plane and installed. Each weighs 64lbs and is capable of firing 750 rounds per minute at a maximum rang of 3,500 feet. Each magazine contains 365 rounds.
The fuel tanks are then topped up. The B-17G has a maximum capacity of 2,780 US gallons with 5 filling points on each wing between the two engines. The tanks are self-sealing Tokyo Tanks made up of a rubber composite divided up into 18 small cells. The tyres are inspected and any small oil leaks from the engines are checked for signs of deterioration. The oxygen supplies are checked. these consist of 18 light metal bottles each giviing 5 hours supply to one an at 30,000 feet.