What is required before moving the thrust levers into the forward thrust range after using reverse thrust?

Moving the thrust levers into the forward thrust range after utilizing reverse thrust is a critical procedure that requires specific checks to ensure safety and proper aircraft operation. The requirement to ensure the REV icon on the Engine Indication and Crew Alerting System (EICAS) is shown in amber or green is essential because this indicator provides crucial information regarding the status of the thrust reversers.

When the thrust reversers are deployed, the REV icon will change on the EICAS to indicate that the aircraft is in reverse thrust mode. Before transitioning the thrust levers back to the forward thrust range, confirming that this icon displays amber or green verifies that the thrust reversers have successfully stowed and that the engines are ready for normal forward thrust operation. This prevents potential accidents that could arise from attempting to apply forward thrust with the thrust reversers still deployed or improperly stowed.

Waiting for a specific period like 30 seconds, checking altitude, or confirming landing gear position, while they may be relevant to overall flight safety, do not provide the immediate and necessary assurance regarding the readiness of the thrust reversers and engine operation status at the moment of switching from reverse to forward thrust.