The industry overall fared worse in the year-over-year comparison amid rising fuel prices, canceled flights and frustrated consumers.
Among 16 airlines, AirTran, Jet Blue and Southwest were atop the rankings, while SLC's dominant carriers, Delta Air Lines and SkyWest Airlines, finished 10th and 13th, respectively. At the bottom of the list released Monday was Atlantic Southeast Airlines, which along with SkyWest Airlines is a subsidiary of St. George-based SkyWest.
The past year ''was the worst year ever for the U.S. airlines,'' said Brent Bowen, a study co-author and professor at the University of Nebraska at Omaha's Aviation Institute.
The annual Airline Quality Rating survey found that more bags were lost, more passengers were bumped, more consumers complained and fewer flights arrived on-time than in the previous year. The overall ''quality score'' the researchers gave the industry (-2.16) was the lowest in the nearly two decades they've been studying the airlines.
The survey comes at a difficult time for the industry given safety issues and bankruptcy troubles that shut down three carriers last week. ATA, Aloha Airlines and Skybus stopped flying because of financial pressures.
Major airlines also have slashed jobs while adding fees for second bags, traveling with pets and booking tickets by phone. And American, Southwest, Delta and United have all had to cancel flights recently to perform safety inspections on some of their planes.
Last month, the Federal Aviation Administration hit Southwest with a $10.2 million civil penalty for missing safety inspections and then continuing to fly planes with passengers on board even after realizing the mistake.
A trade group for the major U.S. carriers, the Air Transport Association, declined to comment on the report, but representatives for Delta and SkyWest said their airlines focus on quality and outperform their peers in some areas.
"The same data on which this study is based - information that is made public by the Department of Transportation every month - shows that Delta was in the top tier among its peers in on-time [performance] last year," spokesman Anthony Black said in an e-mail statement.
"Certainly there is always room for improvement but Delta consistently performs well among its peers in other airline rankings, such as our number two position in the JD Power survey."
Marissa Snow of SkyWest said its employees, too, always are striving to improve the airline's operations. "Quality is a consistent focus."
According to the study, the rate of consumer complaints was up 60 percent last year. US Airways had the most complaints. Southwest had the fewest. In all, complaints were up for 15 of the 16 airlines included in the study. Mesa Airlines was the exception.
About 37 percent of the complaints were for flight problems, including canceled or averted flights, said Dean Headley, an associate professor at Wichita State University and co-author of the study. About 20 percent of the complaints concerned baggage - stolen, lost or damaged. Another top complaint, about 11 percent, was poor customer service.
The Airline Quality Rating study, compiled annually since 1991, is based on Transportation Department statistics for airlines that carry at least 1 percent of the passengers who flew domestically last year.
* Study site: http://www.aqr.aero/
* Transportation Department: http://www.dot.gov
* Delta Air Lines and Northwest Airlines reportedly are once again exploring a merger deal, with Delta's board authorizing a new round of talks, according to the Financial Times. Northwest is said to have proposed a deal that isn't contingent on the two carriers' pilots groups agreeing on how to merge seniority lists, which has stalled earlier efforts.
* Mesa Air Group Inc. filed a federal lawsuit against Delta Air Lines to keep its contract-flying agreement intact, in response to Delta's announcement last week that it planned to end the contract.