FAQ n.115298

If you do not follow the instructions, then you may not be allowed to travel. 

• You may be refused access to the airport terminal building, to the aircraft cabin, or removed from the cabin, according to national/local legislation, if you do not follow the instructions given, which are there for the safety of all. Depending on local regulations, you may face additional consequences as determined by the local authorities.  
• If the aircraft is already in flight, the procedures relating to handling cases of unruly passengers may be applied if you do not comply with the instructions of the cabin crew. Further actions may be taken by the local authorities at the destination airport, in line with local regulations, as a result of actions that endangers the flight and health safety of other passengers and crew members.  

Depending on local requirements or recommendations, you may be subject to certain consequences if you do not follow the mandatory requirements in place at the departure / arrival destination.