Scores of passengers struggled to get refunds when travel plans disrupted.

For U.S. airlines in this time of COVID-19, the number of flights is down, the number of passengers is down, and revenue is definitely down.

One stat, however, has reached stratospheric levels: the number of complaints filed against carriers.

Traveler complaints to the federal government skyrocketed 568.4%, according to information released Thursday by the U.S. Department of Transportation.

So much for United’s friendly skies; 11,274 grievances were filed against the airline. And Delta might be ready when you are, as its old slogan said, but that didn’t prevent 3,840 complaints to the DOT, the vast majority about refunds.

Last year, 102,550 complaints about air travel flooded into the DOT compared with 15,342 in 2019.

“It’s just unprecedented. There’s nothing you can compare it to,” said Bill Mcgee, aviation adviser at Consumer Reports.

Airline flight counts in 2020 dropped to the lowest level since federal reporting began in 1987, according to the DOT.

Airlines canceled thousands of flights, and scores of passengers struggled to get refunds when their travel plans were disrupted as the coronavirus spread around the world.

There was a bright spot: Less-crowded skies meant airlines improved their on-time arrival rate to 84.5% in 2020, up from 79% in 2019.

Passenger counts declined significantly start

ing in March and remained at less than half of normal levels for much of the year.

Passenger counts are still down more than 50% this month, according to airport TSA checkpoints.

“This last year has been really difficult,” Delta CEO Ed Bastian acknowledged during remarks this week. Even now, “demand still is quite soft,” he said.

Bastian is hopeful for a financial recovery at Delta later this year as more Americans are vaccinated and domestic travel returns. But, he said, international travel may not meaningfully recover until “maybe spring of ’22.”

Airlines operated about 4.7 million flights in 2020, down from nearly 8 million in 2019, according to the DOT. Atlanta-based Expressjet, a former Delta Connection regional carrier, shut down entirely Sept. 30.

Though the number of complaints to the DOT is the highest on record, it likely reflects a fraction of the number of travelers frustrated by flight cancellation and refund issues. Many passengers contact their airline but do not file a complaint with the federal government.

Airlines across the board heard from angry customers who encountered problems trying to get refunds. “You can see who the bad players were ... [who] just decided to hold on to people’s money,” said Chris Elliott, a consumer advocate who writes the newsletter Elliott Confidential.

“It almost tells the story of how the airline industry did during the pandemic,” Elliott said.

Of the passengers filing grievances with the federal agency, 1,789 were against Southwest, the second-largest carrier at Hartsfield-jackson International Airport.

Southwest has historically had a low complaint rate.

Frontier, a smaller, ultralow-cost carrier, prompted 5,523 complaints to the DOT in 2020, giving it the highest complaint rate for the number of passengers carried.

Foreign airlines generated tens of thousands of additional complaints as international flights were abruptly canceled during the year. Thousands of other complaints were about refunds from travel booking websites.

Some travelers found they were not necessarily entitled to refunds if they canceled their trips or couldn’t travel due to sickness. In those cases, airlines often offered vouchers or flight credits instead.

The DOT said it has communicated with airlines that received large numbers of refund complaints “to ensure compliance with the refund requirements.”

Travel advocacy groups have pushed for more protections so that travelers can get refunds.

“You pay money, and then something comes along like COVID; your plans change, and you want your money back,” Mcgee said. “These people need refunds.”

Elliott said another round of consumer problems to come could stem from the expiration of travel vouchers that passengers received when they canceled their trips early on.

“Unfortunately, nobody knew that the pandemic would last as long as it did, so their ticket credits are going to expire,” Elliott said.