On a recent Delta Air Lines flight from Newark to Minneapolis, a passenger seated near Stephanie Wolkin downed five mini-bottles of vodka in rapid succession. By the time the plane landed, the intoxicated passenger had become violently ill, and Wolkin, a retired union worker from St. Paul, Minn., had earned 10,000 frequent-flier miles the hard way.

A majority of passengers drink when they fly, according to a new survey by Fractl, a marketing agency in Delray Beach, Fla. More than 8 in 10 passengers say they have consumed alcohol while waiting at the airport, and that number increases to more than 90 percent once in the air. Millennials are 10 percent more likely to be intoxicated on a flight than older passengers, according to the survey.

Alcohol has fueled some horrible in-flight incidents in recent years, including sexual assaults, bloody brawls, and mere loud confrontations. This past summer, Irish discount airline Ryanair publicly called for restrictions on alcohol sales at airports, including a ban before 10 a.m.

Few people actually talk about alcohol on planes beyond the physiological effects of consuming a few beers inside a pressurized aluminum tube.

How much should you drink on board? What should you do when someone next to you is drinking to excess? Have we reached a point where we should limit — or ban — alcoholic beverages during flights?

Los Angeles psychiatrist Brian Cassmassi remembers a red-eye flight to Europe shortly after he obtained his MD. About halfway there, the flight attendants asked whether there was a doctor on board.

"A female passenger had become inebriated from drinking two small airline alcohol bottles and taking her prescribed Ambien," Cassmassi recalls. "She was combative toward the flight attendants and other passengers seated near her. I helped to restrain her and calm her in the galley until we made an emergency landing."

Cassmassi thinks one or two mini-bottles on a flight are usually fine, but it depends on the passenger. Flight crews have to monitor their behavior carefully to ensure they’re not overdoing it, he says. While actual blood alcohol concentration remains the same during flights as it is on land, people can feel the effects more readily because of slightly decreased oxygen levels in the blood, according to Cassmassi.

"Airplanes keep the cabin pressure about 4 percent lower than normal pressure at sea level, which slightly lowers oxygen intake," he explains. "With that dip in oxygen for fuel, the brain is more susceptible to the effects of certain substances like alcohol, and so people can feel more buzzed sooner with a drink."

Among airlines, alcohol availability runs from an outright ban to free drinks. Middle Eastern carriers such as Royal Brunei Airlines, Saudi Arabian Airlines and EgyptAir fly alcohol-free. Some airlines don’t serve adult beverages on domestic flights (Turkish Airlines and many Chinese airlines, for example). A majority of airlines still serve alcohol, but they charge for it outside of business class and first class, where drinks are included in the price of your ticket.

Flight attendants undergo alcohol training using the traffic light system that bars and restaurants use to categorize patrons: green for social drinkers behaving within social norms, yellow for lower inhibitions and inappropriate behavior, and red for impaired motor functions.

When passengers shift to yellow, they cut them off. But when the drinks start flowing at 36,000 feet, flight attendants are outnumbered, and it falls to passengers to ensure that other passengers are not overindulging.

That’s particularly true when passengers start drinking before the flight or bring their own booze.

"Modern manners dictate that before drinking yourself straight into the airsickness bag, you must consider all other passengers alongside you, because they have fewer options than you do," says Sharon Schweitzer, an etiquette expert who operates the consulting firm Access to Culture.

But what if your fellow passenger doesn’t see it that way?

On a Southwest Airlines flight recently, I sat next to a young woman who, whenever the flight attendant came within shouting distance, ordered a white wine. Two chardonnays into a conversation, she started to exhibit all kinds of yellow-light behavior.

Almost the moment I thought, "What am I going to do now?" a stern-faced flight attendant materialized. The passenger tilted her plastic cup toward her, but the crew member slowly shook her head.

"I’m sorry," the attendant said in a not-sorry tone. "We can’t serve you any more."

The woman fell asleep on my shoulder shortly after.

I could have handled that situation differently, experts say. The steps for defusing disagreements involving alcohol on planes are identical to those for defusing any conflict.

First, encourage the passenger to slow down on the drinking. You can hint at that by saying: “Could I get you a glass of water? I hear alcohol dehydrates you on a plane.” (That’s true, but it also is a better way of bringing up the topic of someone’s excessive drinking than saying, “You’re drinking too much!”)

If that doesn’t work, ask a flight attendant whether there is an open seat available elsewhere. (Not always or even at all an option with flights being fuller than in the past.)

Finally, talk to a crew member privately about the passenger’s behavior. At the very least, he or she can cut the drunk passenger off, which will make the rest of the flight a little more bearable.

And if you find yourself in a situation like Wolkin’s? You might want to pack a change of clothes and a package of baby wipes in your carry-on for your next flight. Even if you don’t have a baby.

With another spring break coming up, this may be a good time for U.S. carriers to consider limiting or eliminating the alcohol served on board. It would significantly reduce the number of in-flight confrontations and make flying safer for everyone.

Don’t laugh. For decades, the idea of a smoke-free flight was unthinkable. Now someone’s lighting up on board is not even imaginable.

Christopher Elliott is a consumer advocate, journalist, and co-founder of the advocacy group Travelers United. Contact him at elliott.org.