The nation's airlines generated more complaints and denied passengers seats at a higher rate in 2012 but improved their on-time performance and lost bags at a lower rate.
Those were among the key findings of an annual study on airline service released Monday by professors at Wichita State University and Purdue University.
The study looked at several key airline statistics monitored by federal agencies and weighted them based on what services experts believe are most important to air travelers.
The study's overall airline quality rating score for the industry dropped to -1.11 in 2012 from -1.08 in 2011, according to the report.
Virgin America received the highest score from the study, followed by JetBlue and AirTran Airways. The lowest scores went to United Airlines, Express Jet and SkyWest airlines.
In 2012, the nation's top 14 airlines improved their on-time performance, with 81.8% of flights arriving on time, up from 80% in 2011, according to the study. The airlines did a better job of delivering bags, with 3.07 bags lost or mishandled per 1,000 passengers, down from 3.35 in 2011.
Experts say the industry has improved its on-time performance because it has cut capacity amid several mergers over the past few years. Meanwhile, the experts say, the industry has lowered its rate of lost or mishandled luggage because it has imposed bag fees, prompting passengers to check fewer bags.
The rate of complaints filed against airlines, however, increased to 1.43 per 100,000 passengers last year, up from 1.19 in 2011. The rate of passengers denied boarding because of overbooked planes jumped to 0.97 per 10,000 passengers in 2012, up from 0.78 in 2011, according to the study.
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