It’s back. US Airways and Delta Air Lines’ proposal for a LaGuardia/Reagan National slot swap that is. The two airlines are claiming that the Southwest Airlines/AirTran merger eliminates the antitrust problems. We’ll have to wait and see what the DOT says about that. AirTran’s DCA and LGA slot holdings are close to but still slightly less than what the DOT wanted the two airlines to sell off when the swap was first considered.