Under what conditions should cabin crew immediately notify local airport authorities?

Cabin crew should immediately notify local airport authorities when there is an unauthorized person in a restricted area. This situation represents a significant security risk, as restricted areas are designated to ensure the safety and security of passengers and crew. Unauthorized access can lead to various threats, including potential security breaches or unlawful actions that could jeopardize the safety of the aircraft and its occupants.

While the other situations listed are serious and require attention, they do not automatically trigger the same urgency in notifying airport authorities as the presence of an unauthorized individual in a restricted area. For instance, passenger attempts to enter unauthorized areas may be addressed by the crew on board, as it usually occurs within the confines of the cabin or terminal - areas that the cabin crew are trained to handle directly. Disruptive behavior, although a critical issue, typically requires de-escalation skills and may not necessitate immediate intervention from airport security unless it escalates. Smoke detection in the cabin certainly demands a swift response, but it primarily falls under emergency protocols focused on ensuring passenger safety before it is escalated to local authorities.