Where is airplane fuel stored?

The natural place for fuel is inside the wing. The torsion boxes formed by spars, ribs and skin are sealed and turned into integral tanks, with no bladders or extra containers, so that almost all of the wing's structural volume is put to use. There's an engineering logic to it: fuel weight, spread along the span, counters the lift force that tends to bend the wing upward and reduces loads at the root. That's why fuel management systems burn from the center tank first and save the wing tanks for last, and why a fully loaded aircraft requires a minimum amount of fuel in the wings before takeoff.

Between the two wing halves, beneath the cabin floor, the wing's center box houses a third tank that on wide-body aircraft can be the largest of all. Some long-range models, such as the A330, A340 or A380, add a trim tank in the horizontal stabilizer: during cruise, fuel is transferred aft to shift the center of gravity, reduce the load on the tail and shave off a bit of fuel burn. Business jets and extended-range versions install auxiliary tanks in the cargo hold, and in fighters, with their thin wings, most of the fuel travels in the fuselage behind the cockpit, supplemented by jettisonable external tanks.

An Airbus A320 carries around 24,000 liters split between two wing tanks and one center tank; an A380 holds up to 320,000 liters across eleven tanks (manufacturer data, September 2026). Aviation kerosene weighs about 0.8 kg per liter, so an A380 with full tanks carries more than 250 tonnes of fuel, close to half its maximum takeoff weight. Tanks vent to the atmosphere through surge tanks at the wingtips to avoid overpressure from changes in altitude and temperature.

Each tank has redundant electric pumps, transfer valves and capacitive level probes; the crew monitors lateral balance and, if one wing is heavier than the other, triggers a cross-feed transfer. After the 1996 TWA 800 accident, inerting systems were mandated that fill the empty space of the center tank with oxygen-depleted air to prevent flammable mixtures. And, despite what is sometimes believed, fuel never travels in the cabin: the few fuselage tanks sit in sealed compartments, isolated from passengers and the baggage hold.