Incidents involving unruly passengers in the United States are decreasing.

But the good news may end there.

On average, there were about 500 reports of unruly passengers per month in 2021, according to the U.S. Federal Aviation Administration. In the first three months of 2022, this number fell to about 350 reports per month, according to FAA statistics.

That’s progress, especially considering that there are far more flights than in early 2021, when incident reports reached an all-time peak.

However, it’s still a far cry from the number of in-flight outbursts logged before the pandemic, which from 2014 to 2019 happened about 10 times a month, according to CNBC’s calculations.  

In 2021, nearly 3 out of 4 unruly passenger reports were related to mask compliance, according to the FAA, which monitors flights that depart from or arrive in the United States.

For some, refusing to wear a mask became both a political statement and a marker of personal autonomy, said Sharona Hoffman, co-director of the Law-Medicine Center at Case Western Reserve University School of Law.

Many of these people do not want to be told what to do, and flying is “an environment where they are told what to do — all the time — for hours.”

Rage in the not-so-friendly skies is also a manifestation of anger happening on the ground, she said. For every video of an airline passenger losing it on a flight, there are others at grocery stores, school board meetings, banks and parking lots.  

Covid measures have added to the stress of flying, said Hoffman. Meals, drinks and snacks were taken away at one point, “so all the things that used to distract and entertain people were removed,” she said.

Bryan Del Monte, president of The Aviation Agency, a marketing company for the aviation industry, agreed stress may be behind the increase in unruly behavior.   

“However, I’m under a fair amount of stress and somehow, I don’t go bananas on an airplane, punch out the flight attendant … while 20-30 people film it,” he said.

Threatening or interfering with the duties of a crewmember can result in fines, flight bans, federal criminal charges and jail time. With most passengers armed with video cameras on their phones, there’s also the risk of becoming the unwitting star of a viral video, which can — and has — led to job terminations and deportations.  

But what’s a devastating public tantrum to one person may be an act of gallantry to another, said Hoffman, citing those who many want to be a “hero for anti-mask advocates.”  

Others don’t feel the rules apply to them, said Hoffman, adding that “people are used to thinking they’ll get an exception,” which may have been the case for them with vaccine mandates.

Hoffman said although a lot is at stake for bad behavior aboard commercial flights, “people commit crimes all the time.”

Most don’t think they’ll get caught or punished, she said.

They could be right.

Of the 1,091 unruly passenger reports this year, fewer than 30% have been investigated and just 15% have resulted in “enforcement action,” according to the FAA. Still, that’s higher than the 6% of reports that resulted in enforcement action in 2021, said Del Monte.

“Enforcement action” now means proposed fines, an FAA spokesperson told CNBC. In the past, it included warnings and counseling, but that ended under the FAA’s “zero tolerance” policy which started in January 2021.

Maximum fines have increased too — from $25,000 to $37,000 per violation — and one incident can result in multiple violations, according to the FAA.

But this isn’t enough, said Del Monte, who said much more should be done.

“Fining these people is obviously not a deterrent,” he said. “Most [of] them — $300, $3,000, $30,000 or $3 million — it wouldn’t matter. They’re judgment proof.”

Even fewer people face criminal proceedings, he said. The FAA, which lacks criminal prosecutorial authority, said it referred 37 unruly passengers to the FBI last November. Later that month, Attorney General Merrick Garland directed U.S. attorneys to prioritize the prosecution of federal crimes on commercial aircraft.

“That’s when we started seeing people get referred for criminal prosecution,” he said. “A few high profile cases where these criminals wind up doing 60 months somewhere would put the word out that this is not acceptable.”

Del Monte said he supports Delta Air Lines CEO Ed Bastian’s call for a national “no-fly” list in a letter to Garland in February. In the letter, Bastian said Delta has banned at least 1,900 for mask-related issues alone, as well as increased self-defense training for flight attendants and front-line employees.

Since most problems are related to masks, unruly passenger reports will likely drop once mask mandates end, said Del Monte.

Masks are no longer required on several major European airlines and could end in the United States on April 18, when the federal mandate expires. Asia, on the other hand, is expected to keep mandates in place longer. News of unruly flyers in the region remains scarce thanks in part to a culture of mask-wearing that predates the pandemic.

Yet even with mandates gone, incidents aren’t likely to return to pre-pandemic numbers, said Del Monte.

About 28% of U.S. unruly passenger reports in 2021 were not related to masks, according to the FAA. Ignoring mask-related incidents altogether, unruly passenger incidents still increased some 1,300% last year compared with the five years before the pandemic, according to CNBC’s calculations.

The most violent onboard attacks “have nothing to do with masks,” said Sara Nelson, president of the Association of Flight Attendants-CWA in a statement published Feb.15 in support of a centralized list of banned passengers shared between airlines.

Still, Del Monte said, the problem isn’t likely to go away soon.  

“I doubt sincerely … the ignoramus sod who is suddenly an expert on both epidemiology and the rule of law will be placated by lack of a mask,” he said. “That person will undoubtedly find some other small injustice to create the conditions he’ll wind up fined or imprisoned over.”

Plus, airlines may have to contend with another mask problem then — the “radicalization” of flyers who want the mandates to continue.

“They may replace those who refuse to wear a mask as being unruly,” he said.