What prevents fuel jettisoning past the limits set by federal regulations?

The correct choice is based on the function of low-level circuit and dump limit valves in aircraft fuel systems. These valves are specifically designed to regulate the fuel jettisoning process, ensuring compliance with federal regulations that limit the amount of fuel that can be released during flight.

When the aircraft needs to jettison fuel, for example, to reach a safe landing weight, the low-level circuit ensures that the fuel is not dumped below a certain threshold, thereby preventing excessive fuel release. The dump limit valves work in conjunction with this circuit to prevent the system from jettisoning fuel beyond the federally mandated limits.

In summary, low-level circuit and dump limit valves play a crucial role in maintaining fuel management regulations, allowing for safe operations while still providing the necessary functionality for fuel jettisoning when required.