(CNN) — Air travel can be hard work, whether it's navigating super-long security lines, losing the seat lottery and ending up jammed in the middle of the row, or finding yourself on a plane grounded on the runway, delayed and unmoving for the foreseeable future.
In these stress-inducing scenarios, most of us might plug in our headphones and get lost in a podcast or movie -- or simply close our eyes and try to get some sleep.
For others, the pressure gets too much, the scales tip over into the wrong direction and the perfect storm's created for the unfortunate phenomenon known as air rage.
In the photo above, actors play out a disruptive scenario as part of training carried out by the aviation security company Green Light.
Air rage is a term used for disruptive and unruly passenger behavior, ranging from snapping at the flight attendant, refusing to sit down, brawling with another passenger and even, in the most extreme scenarios, attempting to enter the flight deck or open the emergency exit door.
These situations might be exacerbated, or even directly caused, by excessive alcohol consumption, fear of flying, mental health conditions or other individual issues the traveler is dealing with.
Certainly, they're seemingly ubiquitous on social media -- who hasn't winced at a grainy iPhone video featuring travelers shouting obscenities or terse air stewards manhandling flailing passengers?
Airlines and aviation authorities have been clamping down, with campaigns such as the European Aviation Safety Agency's #notonmyflight initiative shining a light on the issue.
So what's really going on? Is air rage on the rise? And what can we do to ensure peace, quiet and security in the skies?
The International Air Transport Association (IATA) has been collecting data on disruptive passenger behavior since 2007.
The latest available data, from 2017, indicated an average of one incident for every 1,053 flights. In 2016, IATA reported one incident for every 1,434 flights.
It's worth bearing in mind that not every airline that's part of IATA submits data, and not every airline records every instance of unruly behavior.
In 2017, 81 global airlines submitted data for over 900,000 flights.
IATA ranks each unruly behavior incidents on four levels -- minor, moderate, serious and, finally, flight deck breach.
"Relatively few airlines are members of IATA -- and even IATA is only reporting those incidents that are reported to them by its own members," says Philip Baum, managing director at Green Light, a company that provides aviation security training, and the mastermind behind DISPAX World.
Someone who's been voicing concern about disruptive passenger behavior for a long time is Andrew Robert Thomas, editor of the Journal of Transportation Security, professor at the University of Akron and author of the 2001 book "Air Rage."
Thomas traveled extensively for business during the 1990s and early 2000s, becoming very familiar with the aviation process and all the highs and lows that come with it -- including disruptive passenger behavior.
A growth in air rage sometimes gets pinned on the increased security checks and subsequent stresses that have characterized aviation in the years since 9/11.
Aviation has also changed more generally in the past decade or so -- as more people take to the skies, more passengers are crammed into the cabin.
More often than not, people are too close for comfort and tensions run high.
US internal flights are allowed to overbook aircraft to account for no-shows. Passengers are asked if they'll take a later flight, offered air miles or other incentives. But if no one volunteers, the airline will "involuntarily de-board passengers" possibly based on check-time, cost of ticket or status with the airline.
In a memorable and disturbing incident from 2017, a man was dragged off a United flight after he refused to de-board. In this instance, reports concluded that the flight attendants were in the wrong -- but it demonstrates how charged these situations can become.
"The -- particularly Economy Class experience -- for most airlines has gotten a lot worse over time. You're packing more people into a more stressful environment, I think you've really put burdens on flight crews that are really not fair to them," says Thomas.
Air travel can be stressful.
Flight attendant Allie Malis echos this sentiment. Malis has been working as an air steward for American Airlines for five years and has seen a notable increase in disruptive and difficult passengers over even this relatively short period.
"One particular issue that we've been really focusing on -- and our unions been very active on -- is the decrease of personal seat space, which we believe is strongly correlated and in a large part to blame [for unruly incidents]," says Malis, who heads up the government affairs division of APFA -- the Association of Professional Flight Attendants, a union that represents American Airlines flight crew.
Malis also agrees that the increase in passengers and cheaper tickets can mean "corners are cut" -- leading to angry passengers, and flight attendants feeling the brunt of the frustration.
Nevertheless, Malis is keen to stress that extraneous factors can't explain away or validate some of the ways people misbehave on flights.
"I always say passenger issues are flight attendant issues, flight attendant issues are passenger issues," she says. "We are frustrated by the exact same things that passengers are, because the less happy a passenger is, the more difficult our job becomes."
The role of alcohol
An American Airlines passenger became unruly after being denied more drinks on a flight from St. Croix to Miami. CNN's George Howell has the details.
One of the long-cited causes of air rage is alcohol -- after all, the phrase "it's five o'clock somewhere" is never truer than at an airport or in international airspace, where passengers' body clocks could still be tuned to any number of time zones.
Who hasn't marveled at the passengers sipping on the complimentary Champagne in the business class lounge even though it's only 5.30 a.m., been tempted by a couple of glasses of wine to steady nerves before a long-haul flight or internally groaned when you end up next to an already tipsy bachelor party keen on continuing the celebration?
Of course passengers could have taken other substances, too.
The issue with in-air-alcohol is the flight crew have no idea how much passengers have drunk before they got on board. What seems like someone's first or second drink could actually be their fourth or fifth, and tip them over the edge.
Malis says her crew closely observe passengers' behavior from the minute they get on board -- and ground staff will also look for telltale signs of excess alcohol consumption during the boarding process.
And yes, if someone starts displaying signs of drunkenness mid-flight, air stewards can deny that passenger alcohol.
"It happens a lot and without disclosing some of our tricks of the trade, we do have some techniques that we use," says Malis.
"Sometimes just saying the bar is closed is acceptable," she explains. "But sometimes for other passengers, telling them the bar is closed is actually a trigger and makes people angry."
If need be, flight attendants can also confiscate duty-free alcohol from passengers and return it to them when the flight lands.
Paulo Alves, global director of aviation health at MedAire, a company delivering medical and aviation security solutions to airlines, suggests some travelers who feel uncomfortable with flying may use alcohol to "self-medicate."
Alves is keen to debunk what he calls the "myth" that you're more likely to get drunk on a plane than on the ground, due to hypoxia -- a lack of oxygen -- in altitude.
"Hypoxia, however, is very mild in the usual pressurized aircraft cabin, which has a ceiling at around 8,000 feet," he tells CNN.
Richard Dawood, a specialized travel doctor, is more persuaded by the impact of hypoxia -- but he suggests the impact of dehydration on a flight also plays a part.
"When people fly, they actually don't drink enough liquids to balance their fluid losses and also counter the slightly dehydrating effects of alcohol," he tells CNN Travel.
Philip Baum echos this and suggests water should be readily available to all passengers. On many budget flights, it's another item up for purchase, but not otherwise provided.
One of the biggest changes since Andrew Robert Thomas penned "Air Rage" back in the early noughties is the growth of social media.
Now, an air rage incident isn't confined to an airplane cabin. Within seconds it can be live-streamed to the world.
"Every time we walk on the flight, it's 'Do you want to be the next viral YouTube video?'" says Malis.
"You constantly have to remind yourself that you could always be recorded at any time -- and anything you do could be misconstrued."
Most of us see these videos and just feel thankful we weren't on board. But Malis posits others could find themselves persuaded by the bad behavior and its potential lack of consequences.
"Others think it's acceptable behavior -- someone else acted like that, that's a way to get attention or to get what you want or just simply like that's an acceptable way to treat someone else."
Achilleas Achilleos works for the European Union Aviation Safety Agency (EASA), an EU agency concerned with the impact unruly passenger behavior has on aviation safety.
EASA's #notonmyflight campaign involves some 60 European airlines, airports and national aviation authorities disseminating the message on social media that bad airplane behavior won't be tolerated.
Achilleos notes that recorded incidents do lead to more awareness, but clarifies it's not an appropriate response to a disruptive incident.
"We definitely did not encourage people to record," he tells CNN Travel. "What anybody should do when they're faced with an incident is to keep calm and alert the cabin crew."
Vilifying an air rage perpetrator on social media also doesn't do anything to help the issue -- the focus becomes "canceling" the person in question, rather than looking at the wider causes and impact of their behavior.
Paulo Alves points out also medical conditions could be behind the disruption. "Passengers with dementia or autism may be overwhelmed by the unfamiliar in-flight environment," he says.
Defusing the situation
Flight attendants may spend most of the flight handling catering and serving drinks -- but the flight crew are the last defenders, sometimes dubbed "aviation's front line." If there's trouble on a flight, of whatever level of severity, it's up to the flight crew to resolve the situation and ensure the safety of passengers.
"We do have de-escalation training. So we are taught techniques to make sure that small incidents don't become large incidents," says Malis.
A big part of that is pinpointing any potential issues before takeoff. If a passenger is disruptive -- whether that's displaying drunk and disorderly behavior or refusing to comply with instructions -- the captain has final authority on whether that passenger can remain on the flight.
If a situation arises mid-journey, Malis' first action is to try to calm the passenger down, to avoid the situation escalating.
"Whether that's trying to do our best to comply with their demands as best we can within the realm of possibilities [or] sometimes it's bringing in another flight attendant who maybe can cool them off a little bit better -- in case the one flight attendant they were working with was really triggering something," she explains.
If two passengers are having an altercation -- of whatever kind -- the goal will always be to separate them, if possible.
These situations can be more complex, as two passengers have to be calmed down, not just one. It might not be easy to ascertain who is "in the right," if anyone.
If a passenger notices another passenger displaying disruptive or inappropriate behavior, they're advised to alert the cabin crew.
"Passengers should never take action on their own. The cabin crew is trained to deal with this kind of situation, so they know best what they need to do," says Achilleos.
Malis points out a flight attendant's role is to "inform," not "enforce."
"We tell people what the policies are. We're authority figures but we're not able to arrest you, we're not able to enforce penalties or anything like that," she says.
"Only in the direst of situations will we be restraining someone physically -- often with the help of the passengers, the good Samaritans around us -- if there was really some type of issue," especially, she adds, an attempt to breach the cockpit.
The question of physical restraint can be a controversial one, as it comes with a risk of injury to the disruptive passenger.
Richard Dawood stresses the importance of training and careful management.
"It is actually possible to kill somebody by restraining them to the point where they can't breathe properly," he warns.
"Maybe it is necessary to restrain somebody, but how do you do it safely? There are lots of issues around managing the situation, but they need to be addressed."
Air staff are also keen to keep the situation under wraps to reduce the impact on other passengers. Any altercation in the skies has a knock-on effect; it'll likely exacerbate anxiety among nervous fliers and increase everyone's stress levels.
Philip Baum, an aviation security trainer, suggests there should be as much time devoted to training cabin crew to deal with unruly passengers as there is training on emergency landings.
Unfortunately, there's actually a direction correlation between the two -- in the worst case scenario, an extremely disruptive passenger could force the aircraft to make a diversion. Not only is this extremely costly for the airline, it's a pretty disastrous piece of PR.
Consequences and law enforcement
Most of us think behaving badly should have consequences -- and that should extend to the air. That said, laws can make it a bit complicated.
"In most countries, if a person assaults another customer or member of staff in a restaurant, shop or on a train, they will likely be arrested and punished for their offense. If a person assaults a member of cabin crew or another passenger on an international flight, in most cases they will not face prosecution," says Timothy Colehan, assistant director of external affairs at IATA. "This obviously undermines the deterrent aspect."
This is because the Tokyo Convention of 1963 -- which covers offenses committed during flights -- stipulates that the jurisdiction over offenses is conferred on the state where the aircraft is registered.
This means if the aircraft lands in another country, local police don't have authority to intervene.
Some countries -- including the US, Canada, Australia and the UK -- have laws that stipulate they can take control over offenses committed on flights, no matter where the aircraft is registered.
"There are robust laws in place to deal with all disruptive passenger incidents," Andrew McConnell, a spokesperson for the UK Civil Aviation Authority, tells CNN Travel.
"In the worst cases, a disruptive passenger can be charged with recklessly endangering the safety of an aircraft. This carries a potential five-year prison sentence."
The Montreal Protocol 2014 (MP14) attempts to solve this loophole for other countries by enabling prosecution in the state where the airplane lands. On November 26, 2019, Nigeria became the 22nd state to ratify MP14 and it's currently set to come into force January 1, 2020.
"IATA strongly believes that everyone recognizes that there will be consequences for unruly and disruptive behavior on flights," says Colehan. "Civil and administrative penalties can be used to strengthen the deterrent and to supplement criminal prosecutions for the most serious incidents."
A disruptive incident is recreated by actors.
Courtesy Green Light Limited
In the US, the FAA enforces fines of up to $25,000 for disrupting a flight.
Allie Malis wants to see more done to ensure these penalties are enforced.
"When it comes to air rage, our unions' position is that the FAA needs to do a better job at requiring the reporting of these events, and to actually enforce the penalties more aggressively," she says.
"I know anytime something happens in aviation, the airlines are worried about negative press, and so I'm sure they would prefer to handle things quietly. But that's not an option in this modern age of flying, necessarily. We want to make sure that people who do break the law, are made to face the consequences."
Andrew Robert Thomas records incidents of air rage on his website, AirRage.org, replete with wry asides.
"My real purpose in this is just to try to bring attention to policymakers -- to say, look, this is something we need to be dealing with, we need to be having better law enforcement procedures, better punishment, more accountability, those things are happening," says Thomas.
Allie Malis wants this too, but she also wants passengers to practice a bit of empathy next time they feel the scales tipping and the anger rising.
"We do our best with what we can," she says. "Before a passenger decides to blow up on a flight attendant I would love for them to walk a day in our shoes."