Final answer:
In STBY mode, each wing anti-ice valve is independently controlled by its respective standby thermal switch, a critical component for flight safety.
Step-by-step explanation:
In STBY (standby) mode, each wing anti-ice valve is independently controlled by its respective standby thermal switch. Wing anti-ice systems are crucial for flight safety, as they prevent the formation of ice on the aircraft's wings, which can affect the aerodynamic properties and lead to a loss of lift. The standby thermal switch is an important component that ensures the anti-ice system continues to function even if the primary control system fails, providing an additional layer of safety.