The complaints are regarded as indicators of a larger problem because many passengers may not realize they can file complaints with the Transportation Department, which regulates airlines.
At the same time complaints were increasing, airlines were doing a better job of getting passengers to their destinations on time.
The industry average for on-time arrival rates was 81.8 percent of flights, compared with 80 percent in 2011. Hawaiian Airlines had the best on-time performance record, 93.4 percent in 2012. ExpressJet and American Airlines had the worst records with only 76.9 percent of their planes arriving on time last year.
The industry’s on-time performance has improved in recent years, partly due to airlines’ decision to cut back on the number of flights.
“We’ve shown over the 20 years of doing this that whenever the system isn’t taxed as much – fewer flights, fewer people, less bags – it performs better. It’s when it reaches a critical mass that it starts to fracture,” Headley said.
The industry’s shift to charging for fees for extra bags, or sometimes charging fees for any bags, has significantly reduced the rate of lost or mishandled bags. Passengers are checking fewer bags than before, and carrying more bags onto planes when permitted.
The industry’s mishandled bag rate peaked in 2007 at 7.01 mishandled bags per 1,000 passengers. It was 3.07 in 2012, down from 3.35 bags the previous year.
The report’s ratings are based on statistics kept by the department for airlines that carry at least 1 percent of the passengers who flew domestically last year. The research is sponsored by Purdue University in Indiana and by Wichita State.