Airlines have seen an unprecedented rise in disruptive passengers. Experts say it could get worse.

The headlines had barely faded after a Southwest passenger reportedly knocked out a flight attendant’s teeth during an in-flight altercation when the next high-profile example of bad airline behavior emerged. A man was arrested last week after allegedly banging on a Delta cockpit door, demanding the plane land and tussling with a flight attendant.

Less than two weeks apart, the violent incidents - parts of which were recorded by other passengers - served as extreme reminders of the conflict that experts say has risen to unprecedented levels over the past several months as travelers return to the skies.

“If you talked with some flight attendants, they would certainly say this is the worst we’ve ever seen it,” said Sara Nelson, international president of the Association of Flight Attendants-CWA. “It’s pervasive. There is constant conflict on board.”

She added: “I think there’s a potential that this can get worse.”

The Federal Aviation Administration told The Washington Post this week that it has received about 2,900 reports of unruly passenger behavior since Jan. 1. Roughly 2,200 of those involved passengers who would not comply with the federal mandate to wear a face covering. The agency identified potential violations in 446 of those cases and has started enforcement action in 42.

Those numbers have grown over the past couple of weeks: When the FAA last released an update on May 24, it had gotten 2,500 reports of bad behavior with about 1,900 involving masks. The agency has not tracked the number of such reports from airlines in past years, but it said it investigated a total of 1,548 unruly passenger cases between 2010 and 2020.

“Based on our experience, we can say with confidence that the number of reports we’ve received during the past several months are significantly higher than the numbers we’ve seen in the past,” FAA spokesman Ian Gregor said in an email.

And some observers worry the trend still hasn’t peaked as prime summer travel season approaches. The number of passengers continues to creep toward pre-pandemic levels. More people will be crowded onto planes with covid-era restrictions, while at the same time, mask requirements in other parts of daily life are easing.

“I think it could get worse as more and more mask restrictions are lifted throughout the country,” said Jeff Price, professor of aviation management at Metropolitan State University of Denver.

Nelson said it was a “very, very difficult week” after the Centers for Disease Control and Prevention announced that vaccinated people did not need to wear a mask indoors or outdoors in many scenarios. The requirement to wear a mask in airports and on planes, trains and other forms of transportation did not change.

“There is just this level of confusion that also comes into play,” she said.

The return of international flights in greater numbers could also lead to more incidents, said Doug Drury, professor of aviation at the University of South Australia.

“When borders reopen and long-haul travel returns we may see some events related to mask requirements on 6- to 17-hour flights,” he said in an email.

The vast majority of cases reported to the FAA involve refusal to follow the federal mask mandate, which is in place until Sept. 13. But experts say there are many factors playing into the rise of unruly passengers.

Many travelers are starting to move around again after being locked down for more than a year. Some are resentful or defiant about having to wear a mask, and others are on high alert about the mask usage of their neighbors, said psychologist Robert Bor, a director of the U.K.-based Centre for Aviation Psychology.

“Air travel is already stressful,” Bor said. “Here’s a new stress that’s been thrown into the system.”

Pre-existing divisions in the United States aren’t helping. Nelson said flight attendants have found that there are regional patterns to bad behavior.

“There tends to be greater incidents where you are flying out of a place where local and state leaders have said that the pandemic is a hoax, that masks are not necessary, all of those things,” she said.

Price said a portion of the traveling public feels “emboldened” to ignore instructions from authorities.

“Even though those are the rules, they feel that they’re exempt from those rules for whatever reason,” he said. “‘You can’t force me to wear a mask.’ Yeah, actually we can because that’s part of the safety and security of the flight just like we forced you to turn off your cellphone or your laptop.”

Many travelers flying during the pandemic might see the people around them as a threat, especially after spending months adhering to social distancing rules.

“We’ve been told stay six feet away from people,” said Andrew Thomas, an associate professor of international business at the University of Akron and editor in chief of the Journal of Transportation Security. “People are right in your face, and it’s a little weird to say the least.”

Mask tensions have piled on top of anger that flight attendants were seeing among passengers before the pandemic, Nelson said, as people chafed at sitting in ever-shrinking seats, closer to neighbors in economy sections.

“There’s all of these things that existed pre-pandemic that then were absolutely exacerbated because of the pandemic,” she said. “They have been led to believe that the safety steps we are taking are a political decision rather than a public health necessity. That has really been the thing that has lit a match to the kindling that existed before.”

Bad passenger behavior is nothing new; the International Air Transport Association raised an alarm on the issue of unruly passengers a few years ago. The global group said it had gotten reports of more than 66,000 incidents between 2007 and 2017.

And the problem of “air rage,” frequently fueled by drugs or alcohol, has ebbed and flowed over the past few decades, said Thomas, who has written books about the subject and runs the website AirRage.org. He said the numbers tend to increase in line with surges in air travel.

The FAA announced a zero-tolerance policy for bad behavior on planes in the days after the Capitol riot on Jan 6. The flight attendants union said at the time that those who stormed the building should not be allowed to get on flights home.

During a town hall meeting late last month, FAA chief Steve Dickson said he was “appalled” at the behavior the agency had seen on planes and warned of “hefty fines and possible jail time.”

“Covid-19, we all know, has been a trying time for everyone,” Dickson said. “But that’s no excuse for leaving good behavior in the airport or at the airplane door.”

The FAA has publicized several fines against unruly passengers in recent months. Airlines have added disruptive passengers to their own lists of banned travelers. Some have extended their suspension of alcohol sales - a move flight attendants and other observers applauded.

But experts think there are more steps that authorities can take, like providing more education about why masks are still required on planes and restricting alcohol in airports as well as on planes.

Nelson said most important is that everyone involved in air travel - flight attendants, captains, airlines, the FAA and Transportation Security Administration - constantly communicate the rules and expectations for the flying public.

Still, no one can really say what will end the current run of bad behavior.

“When will this stop?” Drury asked. “That is a great question. Maybe when civility returns.”