Who must you ask for permission before disconnecting external power from an aircraft?

The correct choice, which is to obtain permission from the Captain before disconnecting external power from an aircraft, is essential due to several reasons related to safety and operational protocol.

The Captain is ultimately responsible for the safety and operation of the flight and has comprehensive knowledge about the aircraft's systems and current operational status. Disconnecting external power can affect various onboard systems, including navigation, lighting, and avionics. Therefore, ensuring that the Captain has approved this action confirms that it will not interfere with any necessary functions or preparations for the flight.

Operational procedures dictate that all significant decisions, particularly those related to aircraft systems, be communicated and approved by the Captain, as they oversee the entirety of the aircraft's operations during ground handling and flight. This reinforces the chain of command and accountability within the cockpit and the ground staff.

The other roles listed—such as Ground Control, Lead Mechanic, and Flight Attendant—have important responsibilities but do not directly oversee the aircraft's operational authority in this context. Ground Control is focused on air traffic and ground movement, the Lead Mechanic handles technical and maintenance issues, and the Flight Attendant is concerned with cabin crew operations and passenger safety. Each plays a role in the overall operation, but the command responsibility for