Definition
Sealed containers built into an aircraft's wings, fuselage, or other structural areas that hold the fuel supply for the engine(s). In the ditching context, fuel tanks that are partially empty contain trapped air, which contributes to the airplane's buoyancy after a water landing.
Plain English
The containers in the airplane that hold the fuel. When they are not full, the air space inside helps the airplane float for a short time after landing on water.
Context Anchor
Seen during preflight inspection, fuel planning, fuel-system checks, and emergency landing preparation, including ditching or landing on snow.
Derivation
Fuel comes from an older word meaning material used for burning. Tank came to mean a container for holding liquid. Together, fuel tanks means containers that hold the liquid the engine burns to make power.
Why Pilots Care
Fuel quantity and location in the tanks directly affect aircraft weight, balance, and buoyancy when preparing for a ditching.
Analogy
A fuel tank is like the gas tank in a car, but in an airplane there may be more than one, and the pilot may need to manage which tank is being used.
Intuition Check
Do not think of fuel tanks as simple storage boxes only. In an airplane, they are part of the fuel system and can affect engine operation, aircraft balance, and leak or fire risk in an emergency.
Example Sentence 1
With the fuel tanks nearly empty, the airplane floated long enough for the pilot to exit through the cabin door.
Example Sentence 2
The preflight inspection included verifying that both wing fuel tanks were properly vented and free of water contamination.