(CNN NEWSOURCE) For the fourth year in a row, Virgin America is at the top of the list for airline quality.
That's according to the 26th annual national Airline Quality Rating report.
It was released Monday, the same day Alaska Airlines announced that it will buy Virgin America for $2.6 billion.
JetBlue finished second, followed by Delta Air Lines.
Hawaiian Airlines placed fourth with Alaska Airlines rounding out the top five.
Despite overall industry improvement in three of the four categories tracked by the report, customer complaints rose by 38% from 2014 to 2015.
Experts think passengers are annoyed by ticket change fees and a lack of improvement in airline amenities.
The report looks at the 13 largest airlines in the United States over the 2015 calendar year.
It is the work of Dean Headley, a researcher at Wichita State University's business school and Embry-Riddle Aeronautical University Dean Brent Bowen.
