Which item is powered from the Ground Service Bus?

Which item is powered from the Ground Service Bus?

• A. Cockpit dome lights
• B. Cabin crew interphone
• C. Flight deck oxygen system
• D. Pilot's portable laptop

Answer: (A)

Ground Service Bus provides power to equipment used on the aircraft while it’s on the ground and external power is connected. It’s intended for lightweight, ground-focused utilities so preflight tasks can be done without pulling power from the main buses or running the engines/APU. Cockpit dome lights fit this role well: they’re low-demand lighting used during ground operations and can be powered from the Ground Service Bus to help the crew see the cockpit area without engaging the main electrical system. The other items aren’t supplied by the Ground Service Bus in typical operation. The cabin crew interphone is part of the aircraft’s comms system that relies on the normal electrical/essential power arrangement to ensure functionality in flight. The flight deck oxygen system operates from its own oxygen supply and related controls, not from the Ground Service Bus. A pilot’s portable laptop would normally draw power from standard aircraft outlets or the main power system, not specifically from the Ground Service Bus.

Ground Service Bus provides power to equipment used on the aircraft while it’s on the ground and external power is connected. It’s intended for lightweight, ground-focused utilities so preflight tasks can be done without pulling power from the main buses or running the engines/APU.

Cockpit dome lights fit this role well: they’re low-demand lighting used during ground operations and can be powered from the Ground Service Bus to help the crew see the cockpit area without engaging the main electrical system.

The other items aren’t supplied by the Ground Service Bus in typical operation. The cabin crew interphone is part of the aircraft’s comms system that relies on the normal electrical/essential power arrangement to ensure functionality in flight. The flight deck oxygen system operates from its own oxygen supply and related controls, not from the Ground Service Bus. A pilot’s portable laptop would normally draw power from standard aircraft outlets or the main power system, not specifically from the Ground Service Bus.