Which of the following is considered a Level 3 threat?

A Level 3 threat is generally characterized by actions that indicate a significant and immediate potential to endanger aircraft safety or the safety of those onboard. A passenger attempting to open the exit door in flight poses a direct threat to the aircraft, as it could compromise the integrity of the plane and create an emergency situation that can jeopardize the lives of everyone onboard.

In contrast, while making a false bomb claim is serious, and a mentally disturbed individual may pose a risk, neither situation involves an immediate physical action that can endanger the aircraft in the same direct manner as someone trying to force open an exit door. A coordinated hijacking, categorized as a Level 1 threat, represents an organized and well-planned attack that involves multiple actors, and is regarded as the highest level of threat with clear intentions to take control of the aircraft. Thus, the action of opening the exit door in flight is what elevates it to a Level 3 threat, as it directly threatens the aircraft's operation and passenger safety.