B-17. Pilot training manual for the Flying Fortress B-17. Contents
Fuel System
The fuel system of the B-17F consists of 4 independent fuel supplies of approximately equal capacities, each feeding one engine. There are 3 tanks in each wing, with provisions for 2 additional groups of outer wing feeder tanks. These outer wing feeder tanks (Tokyo tanks) are composed of 9 individual, collapsible self-sealing cells per wing. The fuel supply can also be increased by auxiliary installations of re-leasable fuel tanks in the bomb bay.
The fuel in any tank is available to any engine supply tank in the airplane through a fuel transfer system consisting of 2 selector valves and an electrical transfer pump.
There is also a hand transfer pump in the bomb bay as an emergency transfer medium. Fuel booster pumps in the outlets of the 4 major wing tanks eliminate vapor lock between the tank and the engine fuel pump. They also provide fuel to the carburetor when the engine pump fai