The fuel is contained in one integral tank in each wing from rib 0 to rib 17. The capacity of each wing is 1,015 US gallons. Each wing has a wing tank, a collector tank and a surge tank. Each collector tank extends from the wing structure at the rear inboard corner between ribs 0 and 1, top and bottom skin, rear spar and a wall found at stringer 9. The surge tanks are outboard of each wing tank between rib 17 and rib 18.

Rib 11 in each wing tank is not fully sealed and has valves to control fuel movement during aircraft maneuvers. The remaining ribs are open.

There are water drain valves in each wing tank, collector tank and surge tank. Floor-level cutouts through the ribs and across the stringers prevent the accumulation of water. They also allow the water to run towards, and collect at, the drain valves.

The fuel tanks are separated from the passenger compartment by a ventilated air space between the wing and the pressurized cabin.

There is one surge-tank access panel in each of the two surge tanks, found on the outboard side of the wing tanks. They give access to the surge tanks for inspection and maintenance.

There is one collector-tank access panel for each of the two collector tanks, on the bottom skin, forward of the collector tanks. Access to the collector tanks for inspection and maintenance is through the collector-tank access panels and then through access panels in the front wall of the collector tanks at stringer 9.

There are three water drain valves in each wing; one outboard of rib 0, one in the collector tank, and one in the surge tank. They are used to drain water that collects in the fuel tanks and to complete the removal of remaining fuel during defueling. The water drain valve is locked closed when not in use and is operated by applying a manual load on the inner valve. The water drain valve can be locked open to drain the tank during maintenance. It is of double-sealing type for ease of maintenance. The valve has a body with an attachment flange and three electrical bonding strips, and a spring-loaded valve bearing against a seal. The water drain valve and seal can be replaced without draining the fuel tank.

One pressure-relief valve is installed at the end of each wing tank to prevent damage to the wings in the event that the automatic refuel cutoff becomes defective. It is a spring-loaded poppet-type valve. The springs of the hinged arms apply a force on the thrust washer. The valve is held on its seat and is fuel tight. When the pressure in the tank is more than 4 psig (27.58 kPa), the force on the internal surface of the valve opens the poppet. This opening stretches the springs through the two hinged arms. If the tank internal pressure falls below the preset value, the valve returns to its seat. The valves have handles for regular maintenance checks for valve function and for prevention of valve stick. The valves are installed on stack pipes to prevent fuel spill when manually operated.

Three flapper check valves are installed on rib 11 and two on rib 4 of each wing tank. They prevent fuel movement during aircraft maneuvers. There are also 12 flapper check valves installed on the outboard walls of the collector tanks between rib 0 and rib1 of each wing, and the wall at stringer 9. They help keep the collector tanks full through gravity feed.

One gravity filler cap is installed at the center of each upper wing skin. It is a bayonet-type, sealed cap that is used to close the wing-tank adapter assembly. The gravity filler cap has a key lock which is used to lock the cap.

The engines get their fuel supply from the collector tanks. The collector tanks supply a constant amount of fuel to the engines and APU during aircraft movement or if the aircraft is subjected to negative G. The collector tanks are kept full by scavenge ejectors and through gravity feed. Inward-flow flapper check valves let fuel enter the collector tank from the wing tank.

Fuel that enters the surge tanks from the vent lines during aircraft maneuvers is drawn back into the wing tanks by gravity when stable flight is resumed.