Final answer:
The EICAS selector on the reversionary control panel is used to select data and information displayed on the EICAS system in aircraft.
Step-by-step explanation:
EICAS Selector on Reversionary Control Panel
The EICAS selector on the reversionary control panel is used to select data and information that is displayed on the Engine Indicating and Crew Alerting System (EICAS). The EICAS is an integrated system in modern aircraft that provides real-time monitoring and alerts for engine and system parameters.
By using the EICAS selector, pilots can choose which engine information, system status messages, and warnings they want to display on the EICAS screen. This allows them to have a customizable view of crucial information during flight.