There was a surge in long tarmac delays at the nation's airports in February, including several during a snow storm in Dallas.
But consumers' biggest gripe was aimed at United Airlines for refusing to honor super-cheap first-class fares that mistakenly appeared on its website for Denmark on Feb. 11. More than 15,000 people contacted the U.S. Department of Transportation.
The department eventually declined to force United to honor the mistaken fares, noting that "a large majority" of ticket buyers lied when they gave billing addresses in Denmark.
The department said Thursday that 16 domestic flights were stuck on the ground for more than three hours and eight international flights were delayed more than four hours in February.
Federal rules prohibit airlines from holding planes on the tarmac that long, and the department could issue fines.
Eleven of the long delays were American Airlines or American Eagle flights to or from Dallas-Fort Worth International Airport during a Feb. 27 snow storm, the government said.
Overall, 72.8 percent of flights arrived on time in February, down from 76.8 percent in January but up from 70.7 percent the previous February.
Among the 14 airlines that carry enough traffic to report figures to the government, Alaska Airlines had the best on-time rating at 85.1 percent.
Envoy Air, which operates many American Eagle flights, had the worst rating at 53.3 percent. The government said 44 Envoy flights were late at least half the time in both January and February, far more than any other carrier.
A spokeswoman for American Airlines and Eagle, Martha Thomas, said Eagle flights were affected by bad weather and congested airports in the Northeast and Midwest. She added that when airport operations are limited, Eagle flights that use smaller planes tend to be canceled or delayed before American Airlines flights to inconvenience fewer passengers.
Frontier Airlines and JetBlue Airways had the next-worst on-time ratings, both under 60 percent.
The government counts a flight on-time if it arrives within 14 minutes of schedule.
The reporting airlines canceled 4.8 percent of their U.S. flights in February, up from 2.5 percent in January but down from 5.5 percent in February 2014.
Two airlines had much higher complaint rates than the rest — Frontier Airlines and Spirit Airlines. The lowest rate of complaints was at Alaska Airlines, followed by Hawaiian Airlines and Southwest Airlines. The complaint rates didn't include consumer comments about United's mistaken fare, which the department called "opinions."