What must be communicated to the Flight Deck face-to-face before closing the Flight Deck door?

The requirement to communicate that "the cabin is secure for pushback" to the Flight Deck face-to-face before closing the Flight Deck door is critical for ensuring the safety protocols are followed prior to taxiing. This communication confirms that all passengers and cabin crew are accounted for, and the cabin environment is prepared for the aircraft to move.

During pushback, the aircraft is in a vulnerable position as it is being moved away from the gate, and ensuring that the cabin is secure means that all loose items are stowed, passengers are seated with seatbelts fastened, and any potential hazards have been addressed. This step is essential to prevent any problematic situations that might arise during the pushback process, such as passengers trying to move around or items obstructing aisles.

The other options relate to different phases of flight, but they are not pertinent to the pushback phase specifically. "The cabin is secured for landing," for instance, pertains to the preparation for landing, which happens at a different stage in the flight. Therefore, the emphasis on communication regarding the cabin's state before pushback highlights the importance of safety procedures specifically tied to that phase of flight.