What action is necessary during an emergency landing related to the flight deck?

During an emergency landing, preparing to defend the flight deck is critical because the flight deck is a secure area that requires protection from potential threats. This preparation ensures that the crew can maintain control over the aircraft and safeguard both passengers and themselves from any hostile actions.

In the high-stress context of an emergency situation, the crew must be focused on handling the aircraft's landing procedures and protecting the integrity of the flight deck from any intrusions. Engaging in discussions with passengers, initiating routine safety protocols beyond flight deck security, or simply requesting assistance from ground control do not directly address the immediate priority of securing the flight deck. Those tasks can be handled once the situation is stabilized, making the need to prepare for defense the most pressing action during the emergency landing.