AirTran Airways, Southwest Airlines and United rounded out the top of the national Airline Quality Rating study, released Monday.
"JetBlue probably has the right mix of services and management to maintain and secure this top position," said Brent Bowen, a co-author of the report and director of the University of Nebraska's aviation institute. The study is based on Transportation Department statistics.
With Alaska Airlines and America West in the five and six spots, respectively, United was the survey's only top-ranked airline that is not a low-fair carrier.
SkyWest, Comair and Atlantic Southeast Airlines appeared at the bottom of the list of 16 U.S. airlines.
Airlines generally arrived later, lost more luggage and caused more consumer complaints in 2004 than they did the year before, the report found.
Only four of the 14 major airlines rated in both 2003 and 2004 were found to have improved — AirTran, Atlantic Southeast, JetBlue and United.
Airline service is getting worse because more people are flying at a time when carriers have slashed their work forces, said Dean Headley, a co-author of the study and associate professor at Wichita State University.
"Morale's going to be down and they're not going to care if they get the bags to the loading dock in five minutes, 10 minutes or 15 minutes," Headley said.
The seven largest carriers, for example, employed 12 percent fewer people in January 2004 than they did the year before, according to the federal Bureau of Transportation Statistics.
Headley said the aviation system is also being taxed because more planes and more people are flying than they did in the two years after the Sept. 11, 2001, attacks. However, the aviation infrastructure — runways, airport slots and the air traffic control system — is essentially the same as it was in the delay-plagued era just before terrorists hijacked planes and flew them into buildings.