What is the last major action taken during the aircraft preparation for departure?

The last major action taken during aircraft preparation for departure is signaling for push. This action indicates that all essential tasks have been completed, and the aircraft is ready to depart from the gate. Signaling for push is a coordinated effort between the ramp agent and the flight crew to ensure that everything is in order for the aircraft to leave the gate safely.

Prior to this action, several other preparations take place, such as loading cargo, passenger boarding, and ensuring all safety protocols are followed. Once all of these tasks are confirmed to be complete, the agent will signal for push, which typically involves communication with the cockpit and sometimes with ground control. This step is crucial as it marks the transition from preparation to actual movement for departure.