Complaints against U.S. airlines reached a record high in 2024 for the fourth time in the past five years, while flight cancellations and delays also got worse, a new report has shown.

The new report released on Thursday is based on data from the U.S. Department of Transportation and the U.S. Bureau of Transportation Statistics, which was analyzed by the U.S. PIRG (Public Interest Research Group) Education Fund.

According to the report, complaints against 10 of the largest U.S. airlines reached 66,675 in 2024. This marked a rise of nearly nine percent from 2023, even though passenger volume increased by only four percent last year compared with 2023, the report noted.

Teresa Murray, the director of the consumer watchdog program for the U.S. PIRG Education Fund who authored the report, told Newsweek that she was surprised that “complaints in 2024 increased by so much—nine percent” even though passenger volume increased by only four percent last year compared with 2023. “This makes it clear that travelers have found their voice. They know complaints get results,” she said.

For the third consecutive year, Frontier Airlines had the most complaints per 100,000 passengers among the 10 major carriers. Frontier’s complaint ratio of 23.3 per 100,000 fliers was over 10 points higher than the next airline with the highest proportion of complaints—Spirit—which had a ratio of 12.8.

JetBlue had the third worst complaint ratio at 10.4, while the average among the 10 major airlines was 7.2 in 2024. Southwest Airlines had the lowest ratio of complaints, followed by Alaska Airlines and Hawaiian Airlines, the report found.

On the other hand, the volume of complaints for both foreign airlines and travel companies declined. A total of 19,936 complaints were reported for foreign carriers, a drop from 22,617 in 2023, while 1,620 were reported for travel companies such as third-party online ticket agents, down from 2,862 in 2023.

Complaints overall related to air travel, which includes all complaints against both U.S. and foreign carriers as well as ticket agents and others, saw a rise of less than two percent, reaching 89,094 in 2024. However, the 89,094 figure is the second-highest level ever reported, after the record 102,550 complaints overall filed in 2020, about a third of which were targeted at U.S. airlines, the report noted.

The report notes that the top three complaints for several years have been related to refunds, flight cancellations/delays as well as baggage/wheelchairs, with the third category comprising nearly three quarters of all complaints. Other concerns that passengers complained about most include reservations, fares, customer service and issues faced by those with disabilities.

Murray told Newsweek: “Complaints about refunds and delays from 2020 through 2022 caused Congress last year in the FAA [Federal Aviation Administration] Reauthorization bill to spell out that airlines must issue fast, no-hassle refunds if flights are canceled for any reason—bad weather, staffing or a zombie apocalypse, whatever the reason.”

“Congress also spelled out what counts as a ‘significant delay.’ It’s defined as three hours or more,” she added. “That’s now the law.”

The director was also surprised by the rise in cancellations and delays last year, noting that about 22 percent of flights were delayed or canceled, which amounts to 1.7 million flights delayed or canceled in 2024.

The cancellation figures include flights canceled within seven days before the planned departure date, while delays include flights that arrive 15 minutes or more later than their scheduled time.

Murry told Newsweek: “We’re going in the wrong direction and I fear those could get worse in 2025 because of the shortage of air traffic controllers.”

The airlines also reported 437 tarmac delays of more than three hours on domestic flights and 61 tarmac delays of more than four hours on international flights in 2024, the DOT data shows. This marks a rise from 289 tarmac delays on domestic flights and 35 tarmac delays on international flights in 2023.

The domestic tarmac delays reported in 2024 are the most in one year since the tarmac delay rule came into effect in April 2010, which says “airlines can be fined up to $27,500 per passenger if a domestic flight remains on the tarmac for more than three hours without allowing deplaning,” Murray explained in the report.

Asked how economic uncertainty amid tariffs wars and political turmoil in the U.S. and abroad will impact the demand for travel to the U.S. this year, Murray told Newsweek: “It’s too early to tell.”

She added: “But I’ll note that the four major airlines think it could have an impact,” referring to United, Delta Air Lines and Southwest, who have “all said they plan to cut flights in the months ahead” as the “demand could falter.”

If flights are cut while the demand for air travel remains strong, “look for extra-crowded cabins and airports, an increase in connection-busting delays and another record year for complaints for 2025,” she warned.

As noted in her report, global passenger volume was forecast to increase by 6.7 percent this year, compared with 2024, and surpass the 5 billion mark worldwide for the first time, according to the International Air Transport Association.

“I’d be shocked if travel decreases unless things get much worse,” Murray told Newsweek. “There’s still so much pent-up demand post-COVID. But we may not see that 6.7 percent increase.”

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