(NEXSTAR) — Over the last three years, airlines have reported record-setting incidents of disruptive, unruly passengers. That includes passengers accused of assaulting flight crews, opening emergency doors, and refusing to wear masks during the height of the COVID pandemic. 

So how do you know if you’re being unruly? 

Despite the unprecedented rise in passenger incidents, the vast majority of air travelers are not unruly. There are, however, some behaviors that can leave you grounded – and potentially facing criminal prosecution and a federal fine. 

Earlier this month, the Federal Aviation Administration referred 22 unruly passenger cases to the FBI for criminal prosecution review, bringing the second quarter total to 39, the agency said.

These are more serious cases of disruptive passengers. Of the 22 cases referred, 15 involved either threats of assault or the assault of another passenger or a member of the flight crew. Others “exhibited erratic behavior”: refusing to comply with orders from flight attendants, smoking on the plane, making threats, or, on one occasion, a passenger “Airdropped a bomb threat to other passengers.”

Any actions that can impact the safety of the flight crew or your fellow passengers can be considered unruly, which may result in your removal from the flight. 

Last year, the FAA levied two of its largest fines ever proposed. The larger of the two, amounting to nearly $82,000, was against a woman who allegedly fell while out of her seat during a flight from Dallas to Charlotte, North Carolina in July 2021. The FAA said she then threatened to hurt a flight attendant trying to help her, shoved the attendant, and tried to open the cabin door. She allegedly then struck a flight attendant in the head multiple times while the attendant tried to restrain her. Once restrained, the woman “spit at, head-butted, bit and tried to kick the crew and other passengers,” the FAA said.

Other incidents reported in 2021 — when unruly passenger incidents spiked — included a passenger urinating on his seat and a fellow passenger’s bag after refusing to wear his mask, a man who tried making announcements over the plane’s loudspeaker and a woman who had to be duct-taped to her seat after she allegedly assaulted a flight attendant while trying to open one of the plane’s doors.

More recently, a New Orleans man was taken into custody after injuring a flight attendant, authorities said. He was overpowered by several passengers and held down until police arrived, Nexstar’s WGNO reports.

It’s safe to say that if you aren’t doing any of the above actions while you’re flying, you most likely are not an unruly passenger.

There are other unacceptable behaviors airlines have asked passengers to refrain from. 

That includes flying barefoot, which nearly every airline lists as an offense justifying removal of the passenger or a refusal to transport them in their contracts of carriage. 

Other examples listed in contracts of carriage include sexual behavior, having poor hygiene or offensive clothing, being intoxicated, or even making phone calls (there’s a reason you’re instructed to put your phone on airplane mode). 

While the FAA can only impose fines — up to $37,000 per violation in unruly passenger cases — it can refer cases for criminal prosecution. 

There is good news for air travel — according to the FAA, incidents of unruly passengers have dropped by more than 80% since early 2021. Still, the agency acknowledges there is more work to be done. The International Air Transport Association recently called for tougher consequences for unruly air travelers.

As of early August, the FAA says there have been more than 1,170 reports of unruly passengers, surpassing totals seen in 2019 and 2020, but well below the levels reported in 2021 and 2022: 5,973 and 2,455, respectively.

Michael Bartiromo contributed to this report.