Which panel is crucial for switching the display to EICAS?

The display reversionary panel is essential for switching the display to EICAS (Engine Indication and Crew Alerting System) because it allows the crew to manage and control various displays in the cockpit. When a primary display fails or when specific conditions necessitate a transition to alternate displays, this panel provides the necessary controls to facilitate that change and ensure critical flight data is still visible to the pilots.

EICAS is particularly important as it presents key information about the aircraft's engines and systems, highlighting any alerts or malfunctions that require immediate attention. The ability to quickly and effectively switch to EICAS via the display reversionary panel enhances situational awareness and safety, particularly in scenarios where maintaining visibility of engine parameters is crucial for the operation of the aircraft.

The other panels, while important for various functions within the cockpit, do not serve the primary role of managing the display outputs to supply the crew with critical engine and system information in a failure situation.