American Airlines has lost its bid to restore flights between Long Island MacArthur Airport and Reagan Washington National Airport in Washington, D.C.
After weighing applications from four airlines, the federal Department of Transportation last month awarded two available Reagan slots to Southwest Airlines, which proposed operating flights between D.C. and Kansas City, Missouri.
The DOT cited Southwest's bigger airplanes, discount fares and consumer demand for the Kansas City route as the reasons for its decision in a Dec. 15 order.
Southwest has the best chance of "promoting service that produces maximum competitive benefits, including low fares," the DOT order said.
A spokeswoman for the DOT declined to comment further.
The commissioner at the Islip Town-owned airport said the town will continue to look for carriers to use the facility.
"We worked in conjunction with both American Airlines and US Airways in trying to bring this important and well-utilized route back to Islip's MacArthur Airport for our traveling public. We sought and received support from many of our local elected officials from all levels of government in this endeavor," said airport Commissioner Robert Schaefer in an emailed statement. "And while we are disappointed by this recent decision, we remain focused on our negotiations with other interested carriers and making MacArthur a top of the line regional airport."
After a 2013 merger, American Airlines is the parent company of US Airways, one of the two airlines currently operating at MacArthur.
The federal government required the two airlines to reduce the number of slots their planes fill at Reagan as a condition of the merger, and US Airways ended its twice-daily flights between Islip and D.C. in July.
When Frontier Airlines relinquished its two Reagan spots last year, American Airlines officials filed an application for the spots in order to resume service between Islip and D.C., with the support of Sens. Charles Schumer (D-N.Y.) and Kirsten Gillibrand (D-N.Y.).
Two other airlines also applied for the Reagan slots: JetBlue sought one for Jacksonville, Florida, and People Express offered routes to Myrtle Beach, South Carolina, and West Palm Beach, Florida.
The DOT said that American's plan to use a 50-seat Bombardier CRJ-200 plane "would not utilize the limited available capacity" at Reagan as efficiently as JetBlue and Southwest, which offered planes with at least double that capacity.
A spokesman for American Airlines declined to comment.