Air passenger rights: Strike
Airlines can't just cancel their flights because the security staff of an airport is on strike, says the German Federal Supreme Court (BGH).
However, the devil lies in the details: When some of the passengers reach the gate on time, regardless of the strike, and could board the plane, the airline is not allowed to cancel it. Except when they have serious and concrete safety concerns that would justify the cancellation. Such concerns could apply if for example a person got to the departure area without security checks.
In the concrete case, the BGH decided that the affected passengers are entitled to compensation according to the air passenger rights regulation. The strike was not enough reason for the cancellation and didn't classify as extraordinary circumstance.