If the fuel MODE SEL switch is in AUTO, what will happen to the center tank pumps when the slats are extended?

When the fuel MODE SEL switch is set to AUTO, the aircraft's fuel system is designed to manage fuel transfer efficiently based on the operational conditions. The center tank pumps function automatically under this mode, responding to the current state of the fuel system and aircraft's configuration, such as the deployment of slats.

When the slats are extended, indicating that the aircraft is likely in a low-speed, high-lift configuration typically used during takeoff or landing phases, the fuel system automatically activates the center tank pumps as needed. This operational behavior ensures that the center tank fuel is utilized to balance the aircraft's weight distribution optimally and maintain proper fuel flow to the engines.

The automated function of the pumps is critical for managing fuel balance and ensuring that fuel is available when it is most crucial for flight stability and performance. By running the pumps only when necessary, the system conserves energy and minimizes the risk of fuel starvation to the engines. This logic helps pilots maintain control and safety during critical phases of flight.