Before disconnecting ground power and PCA, who must you request permission from?

The correct answer is requesting permission from the Captain before disconnecting ground power and PCA (Pre-Conditioned Air). This is important because the Captain holds ultimate responsibility for the safety of the aircraft and its operations. Before any significant changes are made to the power supply or environmental systems of the aircraft, it is essential to ensure that the flight crew is aware and has agreed to the disconnection.

The Captain may want to confirm that the aircraft systems are ready for such a change or that the disconnection will not impact any final pre-flight checks or preparations. This protocol ensures the safe and efficient handling of the aircraft during ground operations. Effective communication with the flight crew is critical, as they are in charge of the overall safety and readiness of the aircraft for its next phase of operations.