What is the primary function of the Standby Bus?

The primary function of the Standby Bus is to supply backup power for essential flight systems. This bus is designed to ensure that critical systems remain operational in the event of a main bus failure. These essential systems often include instruments necessary for navigation and flight control, enabling the pilot to maintain control of the aircraft even in adverse situations where the main power sources are compromised.

Understanding this function is crucial for safety, as it highlights the importance of having redundancy in aircraft electrical systems. While the other options mention functions related to power and control systems, they do not specifically address the essential backup role that the Standby Bus plays in maintaining operation of critical systems when the primary power source may no longer be available.