(CNN) — Emotional support animals running wild in the aisles, rogue travelers pretending to be airplane pilots and drunken passengers causing emergency landings: last year was defined by some pretty dodgy airplane passenger behavior.
Sure, aviation is stressful -- and being crammed in next to scores of other passengers isn't a recipe for relaxation, but fingers crossed 2020 sees the tide turn, and the era of the unruly fliers comes to an end.
With that in mind, here's what we resolve not to do on airplanes in 2020:
1. Bring an untrained emotional support animal on board
You finally board your flight, sit down and get comfy, only to see that your airplane neighbor is a 70-pound pig.
Unlike service animals, ESAs don't have to be trained to do anything specific -- the idea is they provide comfort through their presence.
Of course, some ESAs might be well-behaved and alleviate their owner's travel anxiety or medical issue.
But a lack of stringent aviation regulation means many others might be untrained and unused to flying and lack the ability to keep still for two, three, four or more hours.
Plus, because flying with a pet is notoriously pricey, some say registering your pet as an ESA is an easy way of working around those extra costs.
The result? Animal-based aviation chaos. There have been reports of emotional support animals attacking flight attendants, defecating and urinating on board, aggravating other passengers' allergies and unwittingly causing emergency landings.
This past year, the airline industry has hit back, with flight attendants complaining, airlines implementing new rules stipulating what kind of animals are allowed on board and which need to be left on the ground.
Back in October 2019, the US Department of Transportation told CNN Travel it was "aware of concerns that individuals may be fraudulently claiming their pets are service animals." The department said it's working on new rules to address this issue.
Beyond more rules and regs, another solution could be designated flights for those traveling with animals.
That's something advocated by Megan Peabody, who has an emotional support pig called Hamlet.
"It would be incredible if there were certain flights, or even an airline, designated for people traveling with animals," she told CNN Travel.
Until that happens, maybe think twice before registering your pet as an ESA on the sly -- or at least get the animal trained up first.
2. Get drunk
Enjoying a glass of wine at 30,000 feet or an inflight gin and tonic is no bad thing, but as on the ground, it's important to drink in moderation.
Alcohol is one of the most frequently cited causes of air rage. It's behind many incidents of in-flight violence, aggravation and abuse, and has led to passenger arrest and flight diversion.
Flight attendants have the right to stop serving a passenger alcohol if they're worried the traveler is about to tip over the edge, but they might not be aware until it's too late.
What seems like someone's first or second drink might actually be the culmination of a morning spent boozing in the terminal.
Flight attendants also have the right to confiscate duty-free alcohol from passengers and return it upon arrival.
Whether you're actually more likely to get drunk on an airplane is debatable -- in November 2019, Paulo Alves, global director of aviation health at MedAire, told CNN Travel that claim is a "myth."
Specialized travel doctor Richard Dawood suggests one of the biggest issues is dehydration.
"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 told CNN Travel.
So make sure you fill up your reusable water bottle before you board your flight, and go easy on the cocktails.
3. Harass fellow passengers
Jessica Van Meir was on a Virgin Atlantic flight for business when she received lewd and harassing messages on the plane's in-flight messaging system. The story sparked outrage.
Everyone on board your flight just wants to get from point A to point B in peace -- and they probably don't want to talk to strangers.
But sexual harassment on board is, like on the ground, completely unacceptable.
Jessica Van Meir was on a Virgin Atlantic flight from London to Washington, DC when she received inappropriate messages on the airline's inflight messaging service.
Courtesy Jessica Van Meir
Virgin Atlantic condemned the behavior -- and said this inflight instant messaging service was being phased out.
Still, back in 2013, the airline was advocating "getting lucky at 35,000 feet" and sending flirty onboard messages, via a video featuring Virgin founder Richard Branson.
A spokesperson for Virgin told CNN: "The video is from 2013. At the time it was created as a playful spoof, however it is not something that would ever be considered today."
4. Buy a ticket but not board the airplane
Most airports aren't places you want to spend any more time than necessary. But in recent years certain airports have branded themselves as shopping-culinary-spa luxury hubs.
The creme de la creme of airports? Arguably Singapore Changi -- the airport with its own waterfall regularly tops the rankings of the world's best airports.
But travelers should remember no matter how appealing it is, it's still an airport, first and foremost, and you're not allowed to go past a certain point unless you're planning to board a flight.
The Singapore Police Force issued a warning reminding residents not to "misuse" their boarding passes.
It's yet another reminder that the romantic comedy trope of running through the airport to stop your loved one from departing -- and possibly leaping over security barriers or buying the cheapest ticket to get into the departure area in the process -- is, in real life, highly inadvisable.
5. Take off your shoes
Airplane passengers are up in arms over bare feet on armrests. CNN's Jeanne Moos
reports on flying feet.
Depending on your point of view, you'll either see this as an incongruous addition to this list, or the most essential.
It's a pretty impressive feat, it's just no one wants to see your feet.
6. Sleep walk
Hand-in-hand with these aviation milestones comes the inevitable question -- how do you successfully sleep on a plane?
You don't want to be a so-called "Ambien zombie," so sticking to a high-quality sleep mask and ear plugs might be a better option.
7. Fake a job/illness/entire identity
Frequent flier Rajan Mahbubani pretended to be a Lufthansa pilot to try and get seat upgrades.
How do you get upgraded at the airport? There are all sorts of theories, but one thing's for certain -- lying about your identity isn't the best plan.
Sure, Leonardo DiCaprio made it look glamorous in the 2002 movie "Catch Me if You Can," but pretending to be an airplane pilot is a definite no-no.
Jayesh Patel, 32, impersonated a senior citizen at New Delhi airport.
Central Industrial Security Force (CISF)
Apparently it worked more than once, but then, in November 2019, he got caught.
Smaller-scale deception is also a bad idea -- and can have unintended consequences. In December 2019, a woman was taken off an American Eagle plane and into custody after she faked an illness in an attempt to get a better seat on her flight.
The flight returned to the airport within an hour of takeoff because the airline believed the passenger was in need of medical assistance.