People are refusing mandatory orders to wear masks on flights, and it's causing mayhem with other passengers

• Most major US airlines require passengers to wear masks on board to help prevent the spread of COVID-19 on planes.
• While most passengers follow the rule, some refuse to wear the masks — leading to flight delays, confrontations, and aggravated passengers.
• Face coverings help prevent the wearer from spreading the coronavirus to others, if they unknowingly have the virus.

It's the new reclined backrest; the window shade, the emotional support animal.

The latest source of tension in the skies: face masks.

As travel demand has slowly ticked up during the pandemic, leading to fuller planes and some airlines ending efforts to facilitate social distancing, most US airlines have mandated crew and passenger masks as a way to limit the spread of COVID-19 on flights.

However, just as in many other public settings such as stores and restaurants, some people are refusing to follow airlines' requirements — and it's leading to confrontation.

Masks have been shown to help prevent the wearer — who may have the virus without knowing it or showing symptoms — from spreading it to others. The more people who go mask-less, the higher the chance of an asymptomatic carrier spreading the virus.

Most major US airlines began requiring passengers to wear masks in early May, but the requirement was initially toothless, with airlines specifically telling crews not to take any action to enforce the rule.

In June, however, in conjunction with the trade organization Airlines for America, airlines announced that they were doubling down on the requirement, introducing enforcement measures that could include banning passengers who refused to cooperate. Small children and people with medical reasons are exempted from the requirement.

According to the airlines, the vast majority of passengers have complied with the requirements. A spokesperson for American said that "some" people had been added to the list, while a spokesperson for Delta declined to share the exact number. A spokesperson for United said that "fewer than 10" people had been banned.

But several high-profile incidents in recent weeks have shown that even as most passengers comply, the mask requirement has the potential to cause conflicts.

Last weekend, a passenger was removed from a Spirit Airlines flight for refusing to wear a mask. According to reports and footage posted on Twitter, the passenger removed his face covering after boarding the flight from New York's LaGuardia Airport to Fort Lauderdale, Florida. Police responded to the plane, and subsequent videos showed that the man, along with other passengers, had been taken off the plane.

The flight ultimately arrived in Fort Lauderdale about an hour and a half late. Spirit Airlines said that the man chose to leave the flight voluntarily, and said that it will continue to enforce the wearing of face masks, according to USA Today.

In June, conservative activist Brandon Straka was removed from an American Airlines flight for refusing to wear a mask. According to a New York Times reporter who happened to also be on the plane, the flight was held up as Straka argued, and other passengers applauded after Straka was removed.

Straka was subsequently banned by American Airlines for as long as the mask requirement stays in place.

Flight attendants have said that enforcing the mask requirement can be difficult.

In a testimony provided by the Association of Flight Attendants-CWA union (AFA), a Spirit Airlines flight attendant described watching a passenger remove her mask during flight, leaving it off for more than 20 minutes as she stirred a vodka cranberry without drinking it at all.

In another testimony, a flight attendant for an American Airlines subsidiary that operates regional flights as American Eagle, PSA Airlines, described arguing with a passenger who boarded a flight and refused to wear a mask. The passenger told the flight attendant that he "woke up in a free country this morning" and described the coronavirus as a "hoax," before ultimately being removed from the flight.

Part of the issue, AFA president Sara Nelson said, is the fact that airlines are left to create and enforce their own rules.

"There is mounting evidence that proper use of masks for all crew and passengers is the most effective action we can take to stop the spread of COVID-19 in aviation," she said. "But we continue to push for a federal mask mandate in aviation. Flight Attendants and other frontline workers who must enforce these policies need the backing of the government and clear consequences for those who don't comply."

It's unclear when the conflicts will end, particularly as demand grows and airlines resume filling middle seats.

Anti-mask activists continue to try and argue against the requirement, with mixed results on different flights. And mask-wearing messengers continue to be irked and delayed by people who refuse, as the Indianapolis Star reported in late-June.

With COVID-19 outbreaks spiking across the United States, it appears unlikely that the mask requirement will go away anytime soon.