What is the purpose of the pump crossfeed valve in fuel systems?

The function of the pump crossfeed valve in fuel systems is primarily to allow for the operation of engines from one tank, which is crucial for both redundancy and operational efficiency. This capability is important in scenarios where one fuel tank may become inoperable or emptied, ensuring that the aircraft can still function safely by using fuel from an alternative source.

Enabling engines to draw fuel from one common source provides flexibility in fuel management, especially in multi-engine aircraft. This is valuable during maneuvers that require different fuel distribution or in emergencies where a rapid response is necessary to maintain engine operation.

While backup fuel supply and balancing fuel loads are important considerations in fuel management, the specific role of the pump crossfeed valve focuses on the operational capability of utilizing fuel from a single tank to power multiple engines. The connection of defueling systems is typically a distinct function and not directly related to the pump crossfeed valve's operation.