Has Southwest Airlines lost its market disruption powers as it quietly enters Washington National?

Southwest Airlines' planned new markets from Washington National Airport set to debut in Aug-2014 make it look increasingly like its Big Three competitors as the carrier appears to be playing to its network strength, adding routes to markets where it holds a strong position.

There was a time when the onetime LCC would strike fear into the hearts of incumbents as its brand appeared across the horizon. Not any more.

Southwest's arrival in DCA looks set to fall far short of the US Department of Justice (DOJ)'s hopes that the airline still has the power to disrupt markets.

Southwest, along with JetBlue and Virgin America, gained new slot pairs at National that American and US Airways were required to divest as part of the process of gaining approval from the DoJ for their merger.

DOJ concluded consumers would benefit from so-called low-fare carriers gaining enlarged access at the slot-controlled airport. But as a result of the divestiture, many small markets are losing air service to National. It is arguable whether Southwest will create any meaningful consumer benefit in the new markets it is introducing from the airport.