The Transportation Department is stepping up enforcement of persistent flight delays with a civil lawsuit against Southwest ...

The lawsuit alleges Southwest illegally operated chronically delayed flights and disrupted passengers' travel plans.

It scored the lowest in safety categories? Dragging its score down. Number nine, Frontier number eight American Airlines, American, by the way, the most expensive and scored the lowest for ...

The department fined Frontier Airlines $650,000 in civil ... this month that Southwest ranked fifth among the 10 North American airlines it evaluated for their on-time performance, with 77.8% ...

Frontier, based in Denver ... a report released this month that Southwest ranked fifth among the 10 North American airlines it evaluated for their on-time performance, with 77.8% of arrivals ...