Threat level 4 corresponds to which type of behavior?

• A. Disruptive Behavior
• B. Attempt or actual breach of the flight deck
• C. Life-threatening behavior
• D. Physically abusive behavior

Answer: (B)

Threat levels escalate with the severity and type of threat, and the fourth level targets the most critical security risk aboard: an attempt to access the flight deck or an actual breach of it. This is why the behavior described as attempting to breach the flight deck is the best match for this level. It represents a direct threat to cockpit security and requires the fastest, strongest crew and security response to protect the aircraft and passengers. Other behaviors—disruptive actions, life-threatening behavior, or physical abuse—are serious and demand immediate intervention, but they do not specifically involve individuals trying to reach or break into the flight deck, so they align with different threat levels.