What does level 3 interference involve?

Level 3 interference is classified as a serious threat to the safety and operation of an aircraft, which includes actions that can cause actual damage to parts of the aircraft. This can involve physical altercations or significant disruptive behavior that can lead to structural harm. In this context, damaging parts of the aircraft is the most fitting description of level 3 interference, as it indicates an imminent danger that may require immediate and decisive action from flight attendants and the crew to safeguard the aircraft and ensure passenger safety.

The other options, while they represent potentially concerning situations, do not escalate to the same level of threat as actual physical damage to the aircraft itself. For example, severe weather conditions, while serious, are typically handled through operational protocols and are not caused by passenger interaction. Smoking on board is prohibited and poses risks, but it does not directly involve damaging the aircraft. Verbal altercations, although disruptive, do not necessarily result in physical damage and may often be managed by the crew without the need for physical intervention.