What condition is required for the center tank to supply fuel during flight?

The center tank must have a confirmed fuel quantity to supply fuel during flight because the aircraft's fuel system is designed to prevent fuel transfer from the center tank if it is empty or nearly empty. This is a critical safety measure to ensure that the engines receive a reliable source of fuel and to prevent any potential ingestion of air that might occur if fuel levels drop too low. The system continuously monitors fuel quantities, and if the center tank is confirmed to have sufficient fuel, it can then activate the pumps to provide fuel to the engines. This ensures that the operation is not only efficient but also safe, minimizing the risk of fuel starvation during flight.

Maintaining fuel quantity in the center tank is vital for optimal aircraft performance, especially when the aircraft is configured for various phases of flight that may require fuel draw from different tanks.