Photo by andertho.

Southwest Airlines will purchase fellow low-cost carrier AirTran for a tidy $1.42 billion plus AirTrans’s sizable debt, according to a report by the Associated Press. Southwest, which is already the country’s largest air carrier based on number of passengers, is making the move primarily to compete with Delta in Atlanta (the one major section of the country where Southwest currently doesn’t fly), but the merger will definitely create some waves in the Washington, D.C. area.

For starters, Southwest may take over AirTran’s gates at National, which would be a most welcome development; AirTran offers non-stop flights to Atlanta, Orlando, Milwaukee, and Ft. Myers, Florida from DCA daily. (Currently, Southwest operates flights out of both Dulles and BWI.) Of course, a potential negative is that, from the sounds of the report, Southwest will be taking on at least some of AirTran’s staffing, which doesn’t boast the most sterling customer service reputation. But Southwest spokespeople have stated in other reports that things like bag fees — for which AirTran charges $20 for the first bag and $25 for the second — will still follow Southwest’s wallet-friendly guidelines.

In any case, the merger is not expected to actually happen until 2012, so don’t get too excited about picking your own seat at National quite yet.