KANSAS CITY, Mo. -- Airlines have a policy which states they may refuse to transport a passenger who appears to be intoxicated or under the influence of drugs.

Federal guidelines support that policy, but when it comes to passengers who get drunk once they're in the air, the lines are not so clear.

For some people, alcohol is a comforting companion on a short hop or a cross-country flight.

"My nana, she drinks when she flies, just because it helps her calm down," said one traveler.

For others, alcohol can be a way to forget you're flying 500 miles an hour at an altitude of 35,000 feet.

"I like a little drinky drink, if you know what I mean," said another traveler.

But for a select few, alcohol can be a catalyst for releasing frustrations, anxiety or just plain anger.

Some experts in the airline industry said alcohol in the air can be a recipe for disaster.

Mary Schiavo, former Inspector General for the U.S. Department of Transportation, has called for limits on alcohol service aboard commercial airliners.

"The number one contributing factor to air rage is alcohol," said Schiavo. "In the long run, you would save yourself a lot of trouble if you simply banned alcohol from the flight, but I don't think that's going to happen any time soon. Neither the government nor the airlines have asked to do it."

But others have, with little success, Schiavo said.

In 2001, Sen. Diane Feinstein threatened legislation if the seven major carriers were unwilling to impose a two-drink limit voluntarily. But nothing came of it.

Industry experts said it is a hot button issue that the airlines have fought.

The following are excerpts from some of the thousands of reports in the Federal Aviation Administration's incident database chronicling passengers behavior.

"... woman became intoxicated, went berserk."

" ... cabin attendant had to guard cockpit door."

" ... Pax had made a hijack threat."

" ... couple engaged in sex acts would not stop when ordered to by crew."

All of these passengers' actions were attributed to too much alcohol. And in those same FAA reports, flight attendants urge airlines to make changes.

"Flight attendants are in trouble if we cut if off and we're in trouble if we don't. I'm not a police man or counselor. It really should be removed from every airline!" said one flight attendant's complaint.

"Whatever you see in the databases of the federal government or other databases about air rage and drunken passengers, in my opinion, seriously underestimates what's going on," said Todd Curtis, Aviation Safety Analyst and founder of AirSafe.com.

There are reportedly some 5,000 air rage incidents each year.

"Congress looked into this and they found in almost every case of air rage alcohol was involved," said Schiavo.

"The airlines and FAA tolerate this level of risk to keep the passengers happy, so I'm afraid unless something really, really catastrophic happens such as a drunken passenger killing someone we won't really see a policy change here."

But that may have already happened.

In 2007, a passenger on board a US Airways flight to Albuquerque became intoxicated on the flight, witnesses said. A couple of hours later, the same man was driving North on an interstate into oncoming traffic. He smashed head-on into another car, killing himself and five of the six family members in the other vehicle.

The incident led to a state ban prohibiting US Airways from serving alcohol on the ground or in the air over New Mexico.

"There have been incidents where there have been deaths, but to date there has been no plane brought down because of alcohol. And until that happens, the FAA and the airlines will win on that point, that it's not a big safety risk even though a few people have died," said Schiavo.

KCTV5 News went undercover to see how free-flowing alcohol would be on a flight. The producers boarded a Continental Airlines flight from Kansas City International Airport to Albuquerque with a stop in Houston.

On the first leg of the journey, which lasted just over an hour, the KCTV5 undercover producer was able to order six mini-bottles of vodka and rum. Each bottle is about 1 1/2 ounces of 80-proof liquor.

The producer was cut off only when the liquor had been locked up for landing.

On the connecting flight from Houston, the undercover producer ordered even more.

"Can I get four?" he asked a flight attendant.

And then, "Can I get another four?" he asked.

Within 20 minutes on the flight, the undercover producer was served eight drinks with no question.

During the one-way trip, he bought a total of 14 liquor bottles.

"It's very difficult to get the flight attendants' attention and say, 'Hey, I'd like to have an extra meal or two, but it's very easy to get their attention for an extra drink or two," said Curtis.

In a 2001 report, the Association of Flight Attendants named "free flowing alcohol" as a significant contributing factor in the cause of air rage, and called for limits on drink service.

"I think the flight attendants would be the first to say, 'Yes, give us a clear cut-off point and make sure that people know we're here for safety. We're here to save your life in the event that something happens and not to mix the perfect martini,' " said Schiavo.

KCTV5 News contacted seven of the major airlines about their alcohol policy.

Not one airline places a specific limit on the number of drinks a passenger can purchase.

Instead, flight attendants and the crew are responsible for cutting off a passenger before they become unruly.

Continental sent the following statement: "Crew members are to use good judgment and communicate with each other when serving alcoholic beverages to customers."

The FAA would not provide anyone to talk about the matter on camera, but a spokesman said, "... our rules allow passengers to only consume alcohol that is provided by the airline." And that it is "...an airlines choice..." as far as "...what they serve..." "how much they serve to passengers is up to them."

"Airlines make money selling alcohol," said Schiavo. "So, airlines say it really affects their bottom line and it's an important money maker for them."

Ultimately it may take a major catastrophe involving alcohol in the air to change current policies, some experts said.

"It hasn't risen to the level where an entire aircraft has been taken down or that many people have been killed, and I'm afraid that unless and until that happens, there won't be a real desire on the part of the FAA to take a look at this issue and to make policy changes," said Curtis.

With the current economy and fuel prices, airlines, like many other businesses, have been working to maintain or increase revenue streams.

The major airlines reported revenues from the newly created baggage fees doubled from 2007 to more than a billion dollars in 2008.

But, industry experts said the total generated by alcohol sales is a "closely guarded secret."