If AC power is lost, how should AC power be reestablished?

To reestablish AC power after it has been lost, the most appropriate course of action is to follow established safety protocols, which typically involve powering down the airplane. This approach ensures that any possible underlying issues can be addressed safely and effectively before attempting to restore power.

When an aircraft experiences an AC power failure, it’s crucial to prioritize safety and evaluate the situation thoroughly. Powering down the airplane allows for a complete assessment of the electrical systems and helps to prevent further complications. It also provides an opportunity to verify that there are no ongoing electrical faults that could pose safety risks during attempts to restore power.

The other options do not address the need for a systematic safety approach following an AC power loss. Utilizing an emergency power checklist is often part of managing such situations, but the initial step focuses on ensuring safety through proper shutdown procedures. Waiting for instructions from ground control does not empower the crew to take immediate, necessary action. Attempting to restart the AC system immediately without first ensuring a safe environment might overlook potential electrical hazards. Therefore, following safety protocols and powering down the aircraft effectively addresses the situation.