Customers gave Seattle-based Alaska Airlines particularly high marks in four of seven measures — flight crews, boarding/deplaning/baggage, check-in and reservations.

For the fifth year in a row Alaska Airlines ranked highest in customer satisfaction among six major North American airlines, according to a survey by J.D. Power and Associates, a global hospitality information services firm.

Customers gave Seattle-based Alaska particularly high marks in four of seven measures — flight crews, boarding/deplaning/baggage, check-in and reservations.

Discount carrier JetBlue ranked highest among a half-dozen low-cost carriers, followed by Southwest Airlines.

Although customer satisfaction with airlines improved for a second consecutive year, dissatisfaction with cost and fees continued to persist, based on responses from 13,500 passengers who flew between May, 2011 and last April.

Compared with a similar survey taken a year earlier, satisfaction with base fares declined for every airline. When it came to costs and fees, only Air Canada, which ranked second after Alaska in overall satisfaction, and Southwest Airlines improved their ratings.

Passengers of both low-cost and traditional network carriers expressed the highest levels of satisfaction with the check-in and reservation processes since 2006.

“Despite initial declines in satisfaction with increased automation of check-in and reservations, passengers have adjusted their expectations during the past several years and now appear more satisfied with the convenience and speed that technology has enabled, while airlines benefit from reduced costs and greater efficiencies in these areas,” said a statement by J.D. Power’s Stuart Greif.

Alaska charges most customers $20 for the first checked bag, but promises a $20 discount coupon or extra frequent flier miles if luggage is not at the carousel within 20 minutes after arrival.

US Airways ranked last among the major carriers in J.D. Power’s survey. Frontier Airlines finished last among the low-cost airlines. More details at www.jdpower.com.

Carol Pucci: cpucci@seattletimes.com. On Twitter @carolpucci.