According to a new report by the United States Public Interest Research Group, the U.S. Department of Transportation received 67,000 complaints about domestic airlines and over 89,000 complaints when international airlines entered the picture.
That number is 9 percent higher than the 2023 figure, while the volume of passengers rose by just 4 percent in the same time.
The report found that flight cancellations and delays also increased in 2024, with nearly 1.7 million flights having been canceled or delayed last year. That number accounts for around 22 percent of flights within the United States and could be part of the reason complaints increased, the study suggests.
“We're heading into summer, which is peak flying season,” says Danny Katz, executive director of the Colorado Public Research Group. “Unfortunately, airline complaints reached record highs last year and we expect more people to fly this summer. But some airlines are scaling back service and we have the air traffic control problems so, now more than ever, travelers need to be prepared before they purchase a ticket and before they head the airport.”
Katz refers to air traffic controller shortages that have caused problems at Newark Liberty International Airport as pilots have been unable to communicate with air traffic control. Earlier this month in Denver, over twenty pilots reported being unable to communicate with air traffic control for up to six minutes.
At the same time, economic uncertainty has caused airlines including Delta, Southwest and United to announce they will cut the number of flights offered in the months ahead.
“If they do reduce flights and demand remains strong, however, look for extra-crowded cabins and airports, more missed connections and another record year for complaints for 2025,” the report warns.
Katz points out that the complaints in the report are generally registered with the DOT after the customer couldn’t reach a resolution with their airline so the number likely doesn’t even represent the breadth of the issues people faced in 2024.
Frontier Stands Out as Worst Airline in 2024
To the surprise of few, the airline with the most complaints last year was Frontier. The notorious budget airline saw 23.3 complaints per 100,000 passengers. Spirit came in second, at 12.8 complaints per 100,000 passengers. The airline with the fewest complaints per 100,000 passengers was Southwest, with just 1.5, followed by Alaska, with 2.6.Frontier has ranked as the worst airline for three years in a row when counting complaints, according to the PIRG report.
“There's clearly a difference, and we think that's important information for people to take into account before they purchase their tickets,” Katz says.
Although Frontier passengers complain a lot, the airline is actually one of the best at handling baggage. The three airlines that mishandled baggage the least in 2024 were Allegiant, JetBlue and Frontier. Those that mishandled baggage the most were American, United and Alaska, according to the report.
Of the top ten United States airlines, around 2.7 million checked bags, wheelchairs or scooters were mishandled. Mishandled baggage is generally lost or damaged. Of that 2.7 million, 11,357 mishandled items were wheelchairs and scooters. Those numbers represent a slight improvement from 2023, the report notes.
What didn’t improve was flight performance. The report found delays and cancellations both increased in 2024, with on-time arrivals occurring less than 78 percent of the time. In 2024, nearly 1.7 million flights were delayed or canceled, according to DOT data.
Frontier also led the way on delays, with JetBlue and Spirit close behind.
The airlines that cancelled the fewest flights in 2024 were Southwest, Hawaiian and Delta. The three airlines with the best on-time records last year were Hawaiian, Delta and United, according to the report.
But at Denver International Airport, the numbers were a little more promising.
Denver Airport Performs Well, but Has Rising Tarmac Delays
At Denver International Airport, flights arrived on time 80.1 percent of the time, which is higher than the United States average of 79.8 percent, according to the report. Flights left on time from DIA 76 percent of the time, which is slightly below the 77.9 percent national average.The best month to fly into Denver was October, when 88.5 percent of flights arrived on time. The worst month was May, when just 73.4 percent arrived on time.
“The fact that Denver International Airport is slightly better, that's likely thousands of flights or hundreds of flights so it makes a difference,” Katz says, adding that on-time arrivals and departures are especially helpful for those who may be stopping over in Denver or who are traveling internationally with multiple legs.
A troubling trend in 2024 was the rise in tarmac delays, where passengers are trapped on the plane waiting in limbo. In 2023, there were 289 tarmac delays of over three hours on domestic flights and 35 tarmac delays of over four hours on international flights. In 2024, the numbers jumped to 437 tarmac delays for domestic flights and 61 tarmac delays on international flights.
“It's really startling to see how many more situations there were where planes and people were stuck on planes on the tarmac well beyond what the law says is allowed,” Katz says. “There's heavy fines that should be kicking in to stop tarmac delays, but clearly something is not working.”
Airlines can be fined up to $27,500 per passenger in those cases; the report suggests the DOT should assess those fines in full to bring down the number of tarmac delays.
Additionally, the report recommends DOT enforce more accountability on airlines.
“Congress should allow state attorneys general to enforce federal consumer protection laws involving the airlines,” the report states. “Most states want to and should be able to do this, but they can’t. Airlines are just about the only industry that is protected from state enforcement of consumer protection laws.”
Colorado Attorney General Phil Weiser has called for Congress to give state attorneys general legal authority to take action against problematic airlines.
How to Make Flying Easier
To protect themselves, CoPIRG suggests passengers should know their rights. When delays or cancellations occur, airlines have certain legal responsibilities to compensate or make up for those problems, which CoPIRG has outlined in an informational tip list.“If your flight has been canceled for any reason whatsoever, then you are entitled to a refund,” Katz shares as the main takeaway.
To avoid unexpected obstacles and delays on travel days, the organization also suggests flying in the morning and flying directly whenever possible.
“Here in Denver, we have a decent opportunity to do that because Denver has so many major carriers and so many direct flights,” Katz says. “We recommend buying tickets directly from the airlines versus third-party travel websites, and use a credit card where you can, because you'll have some additional consumer protections when a flight is canceled or if you need to get a refund.”
Tracking your flight using flightaware.com and putting trackers in your checked luggage are other ways to ease travel woes, Katz suggests.
“When we look at this summer season, analysts expect more passengers, but there's also probably going to be less service, and we have air traffic controller problems as well,” Katz says. “People just need to do more up front to avoid the kind of travel hassles that could happen. ...Clearly, we need airlines to be doing a better job."
