What signifies the activation of the R ENGINE FIRE pushbutton?

The activation of the R ENGINE FIRE pushbutton is indicated by arming both fire bottles. When this pushbutton is engaged, it signifies that the crew is taking action to manage an active fire situation by preparing the fire extinguishing system for deployment. This involves arming the fire bottles that contain the extinguishing agents necessary to suppress the fire in the affected engine area.

This step is crucial in emergency procedures, as it ensures that the firefighting equipment is ready to be activated if the situation escalates, providing a critical response to mitigate the threat of fire and protect the aircraft and its occupants. The correct response emphasizes the importance of preparedness in emergency protocols.