The nation's airlines are reporting fewer delays and overbooked planes, and less lost luggage. So why are passenger complaints up?
In the first six months of 2015, airline passengers on U.S.-based carriers filed 9,542 complaints with the U.S. Department of Transportation, a 20.3% increase over the same period in 2014, according to data released Tuesday.
Airline critics say the problem is that airline service has declined since a series of mergers has put control of 80% of domestic flights in the hands of four carriers: Southwest, United, American and Delta airlines.
"Service has continued to deteriorate at an accelerating rate," said Paul Hudson, president of flyersrights.