Despite profits soaring to levels not seen in years, airline service was a mixed bag in 2013, according to the latest Airline Quality Ratings.
The good news: The quality of service hit an all-time high, with carriers bumping fewer travelers from flights and customer complaints to the U.S. Department of Transportation dropping by 15 percent.
The bad news: Airlines did a worse job when it comes to handling bags and arriving on time.
"The indicators show us a mixed bag, some indicators got better, some got worse," said Dean E. Headley, an associate professor of marketing at Wichita State University and co-author of the annual report. "We have about 15 airlines that we track and for the most part, about half of them got better and half got worse."
Headley and his co-author Brent Bowen, dean of the College of Aviation at Embry-Riddle Aeronautical University, have calculated the Airline Quality Rating annually since 1991.
The annual rating of airlines is calculated by measuring how carriers performed in four categories: on-time performance, mishandled bags, denied boardings and customer complaints.
All four categories are statistical data points measured by the Transportation Department.
The top-rated airline in 2013 was Virgin America. It was the second year in a row the airline topped the list. Here's a look at the top 15.
Two airlines stood out in the annual report on service.
United improved its performance in all four categories. While that is certainly encouraging for United travelers, Headley says the airline had plenty of room for improvement.
"They had a horrible complaint rating a year ago and they really had nowhere to go but up," he said.
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By comparison, Southwest, which is in the midst of completing its merger with AirTran, saw its performance drop across the board. Headley said that could be a sign Southwest is struggling with growing pains.
"Many people always prefer Southwest Airlines, but yet their system is getting a lot more complex," he said. "They are adding a lot of routes, they are growing, and we all know that is a difficult job in today's environment."
Overall, the industry has come a long way from 2007 when the AQR recorded its lowest scores.
—By CNBC's Phil LeBeau.