Plain English Meaning

A valve setting that lets fuel from one tank feed an engine on the other side of the airplane, so you can even out fuel between the wings or keep an engine running if its normal tank is unusable.

Full Definition

A fuel system arrangement on multi-tank or multi-engine airplanes that allows fuel from one tank (or one side of the airplane) to be routed to an engine on the opposite side, or to any selected engine. It is used primarily to manage lateral fuel imbalance or to continue feeding a running engine after the loss of an engine on the other side.

Context Anchor

Seen in fuel-system descriptions, cockpit fuel selector use, abnormal procedures, and multi-engine airplane operations.

Derivation

‘Crossfeed’ is a plain compound: ‘cross’ ( to the other side) and ‘feed’ (supplying fuel). The name describes exactly what the system does — it feeds fuel across to the other side of the airplane.