Washington • Airline passengers are getting grumpier, and it's little wonder, according to private researchers.
Seats are shrinking, more people are stuffed onto planes, and more people with tickets are being turned away because flights are overbooked.
The researchers who analyzed federal data on airline performance also said in a report released Monday that consumer complaints to the Department of Transportation surged by one-fifth last year, even though other measures such as on-time arrivals and mishandled baggage show airlines are doing a better job.
Virgin America did the best job for its customers among leading U.S. airlines last year, as carriers overall had their second-best performance in the more than the two decades since quality of service first started being measured.
The report ranked the 14 largest U.S. airlines based on on-time arrivals, mishandled bags, consumer complaints and passengers who were turned away.
Airline performance in 2012 was the second highest in the 23 years that Wichita State University in Kansas and the University of Nebraska at Omaha have tracked the performance of airlines. The airline's best year was 2011.
Besides being the overall leader, Virgin America also did the best job on baggage handling and had the second-lowest rate of passengers denied seats. United Airlines, whose consumer complaint rate nearly doubled last year, had the worst performance. United has merged with Continental Airlines, but has had rough spots in integrating the operations of the two carriers.
Regional carrier SkyWest, based in St. George and a principal carrier at Salt Lake City International Airport, had the highest involuntary denied-boardings rate last year, 2.32 per 10,000 passengers.
The number of complaints consumers filed with regulators overall surged to 11,445 complaints, up from 9,414 in 2011.
"Over the 20-some year history we've looked at it, this is still the best ... airline performance we've seen," said Dean Headley, a business professor at Wichita State University, who co-wrote the annual report.
Despite those improvements, passengers have plenty to complain about, Headley said. Shrinking seats, full (and overly full) planes are commonplace, as are instances in which customers who have bought tickets being turned away because flights are overbooked.
"The way airlines have taken 130-seat airplanes and expanded them to 150 seats to squeeze out more revenue, I think, is finally catching up with them," Headley said. "People are saying, 'Look, I don't fit here. Do something about this.' At some point airlines can't keep shrinking seats to put more people into the same tube."
The industry is even looking at ways to make today's smaller-than-a-broom closet toilets more compact in the hope of squeezing a few more seats onto planes.
The rate of complaints per 100,000 passengers also rose, to 1.43 last year from 1.19 in 2011.
United's 2012 ranking doesn't reflect its experience over the past six months, in which the airline has made significant improvements in performance, company spokesman Rahsaan Johnson said in an email.
The rate at which passengers with tickets were denied seats because planes were full rose to 0.97 denials per 10,000 passengers last year, compared with 0.78 in 2011.
It used to be in cases of overbookings that airlines usually could find a passenger who would volunteer to give up a seat in exchange for cash, a free ticket or some other compensation with the expectation of catching another flight later that day or the next morning. Not anymore.
Because "flights are so full, there are no seats on those next flights. So people say, 'No, not for $500, not for $1,000,' " said airline industry analyst Robert Mann Jr.
But not every airline overbooks flights in an effort to keep seats full. JetBlue and Virgin America were the industry leaders in avoiding denied boardings, with rates of 0.01 and 0.07, respectively.
United Airlines' consumer complaint rate was 4.24 complaints per 100,000 passengers. Southwest had the lowest rate, at 0.25. Southwest was among five airlines that lowered complaint rates last year compared to 2011. The others were American Eagle, Delta (the dominant carrier in Salt Lake), JetBlue and US Airways.
Consumer complaints were significantly higher in the peak summer travel months of June, July and August when planes are especially crowded.
"As airplanes get fuller, complaints get higher because people just don't like to be sardines," Mann said.
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 that 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.
Virgin America tops out of 14 airlines in quality survey
1 • Virgin America *
2 • JetBlue (3 position last year)
3 • AirTran (1)
4 • Delta (6)
5 • Hawaiian (2)
6 • Alaska (5)
7 • Frontier (4)
8 • Southwest (7)
9 • US Airways (8)
10 • American (10)
11 • American Eagle (15)
12 • SkyWest (9)
13 • ExpressJet *
14 • United (12)
(* new to rankings and qualified by carrying at least 1 percent of domestic passengers)