Alaska Airlines will focus on growing its core capacity in 2015, with the planned 11% increase in departures from Seattle/Tacoma International airport at the centre of its strategy.

“2015’s really going to be about an investment in our core,” says Ben Brookman, director of network planning at the Seattle-based carrier, on the sidelines of World Routes in Chicago.

Alaska has detailed plans for 27 new departures for a total of 280 at its hometown airport to cities it deems “core” from March 2015. Destinations seeing frequency additions include Boise, Chicago O’Hare, Los Angeles, Orange County and Sacramento.

The additional flights are made possible extending the leases on four Boeing 737s, including three 737-400s, and exercising some of its options for 737-900ERs.

The frequency additions, as well as the replacement of smaller 737s with larger 737-900ER models, will drive available seat mile growth in 2015.

Terminal space at Seattle/Tacoma is constrained but Brookman says that Alaska still has space even with its expansion plans. The Port of Seattle is working on an eight-gate extension of the North Satellite at the airport for the airline with a tentative opening by September 2019.

Alaska is coming off a number of new route launches from Seattle, including Baltimore, Detroit and Albuquerque this month and New Orleans and Tampa in June. Cancun service will begin in November.

“The bottom line is that the flights are full and the results are really good,” says Brookman on the new routes. Alaska is waiting the new routes, as well as recent additions from Portland and Salt Lake City, to mature before they consider any additional frequencies, he adds.

Source: Cirium Dashboard