We have been there before, on a flight next to someone who let's just say, not ideal. Taking up too much room, what happens when they fall asleep in your lap? Abc's nick watt with the contenders... See More
We have been there before, on a flight next to someone who let's just say, not ideal. Taking up too much room, what happens when they fall asleep in your lap? Abc's nick watt with the contenders tonight of worst passenger ever? Reporter: We're talking about a volatile mixture of crowds, delays, security, fear of flying, screaming babies and a bucket load of liquor. And anything can happen. What about this? A pair of tipsy moms taking the security check too seriously. And then, there's this. A sweet senior falling in with the wrong crowd en route to cabo. Funnyman hal sparks has seen it all. Some people just aren't good in normal life, and they get on a plane and they don't understand how it stays in the air. They're slightly claustrophobic, agoraphoc. They all come together on a plane. Reporter: Heather poole is a flight attendant. You're on the front line. I'm the punching bag. Reporter: She says it's a potential powder keg up there. You've got half a millimeter between the person sitting next to you. And there's 160 passengers in a flying tube, at 30,000 feet. reporter: NOW FOR A MORE Buttoned-down perspective, mary schiavo, a former inspector general for the department of transportation. Alcohol and aviation do not mix. Reporter: She's now a lawyer, who defends passengers accused of being unruly. She's talking, you know, kristen wiig on "bridesmaids." I am ready to party! Reporter: But for our unscientific survey of the worst airline passengers, let's just start with the naughty nakeds. Full disclosure. I did -- when I was stuck over christmas one year, I met a girl at the airport and we pretended to be a couple, so we could get on the flight together. By the end of the flight, we were. That's all I'm saying. I myself don't usually touch any blanket on the plane that isn't wrapped, for that reason. And it turns out, they were each married to other people. So, the consequences were great. Reporter: Even more alarming, the solo nude. Imagine you're rolling the cart back, and you get to the last row, and there's a naked lady sitting in the row. But the great thing about her was she still had her seatbelt on. Reporter: That's just unsanitary. Next, the biggest passengers. The belligerent boozers, like our duct taped man, who apparently drank a bottle of duty free liquor on a flight from iceland to jfk and started screaming "the plane is gonna crash," so he was taped to his seat. Listen to the moaning. But those were the passengers who duct taped him, did you see that? Reporter: In-flight intoxication is such a problem in russia that -- russian lawmakers are thinking of banning people from carrying duty-free alcohol onboard. Here's the catch though. There is no law in russia that would allow airplanes to punish, much less restrain unruly customers. Reporter: Since this news report aired, russia's largest carrier came out in support of making boozy behavior onboard a criminal offense. Just last week jenny lauren, niece of ralph, was fined $2,700 for allegedly getting drunk and air ragey. A flight attendant claims lauren called her a "fat, ugly, unhappy blonde ." Lauren pled guilty, but later told "the new york post" the allegations are all lies. She claims flight attendants "threatened me." The law is very strict about alcohol up in the air. An airline is not allowed to board a passenger who appears to be inebriated. And an airline cannot, by federal law, serve any passenger to the point of inebriation. Reporter: Do you cut people off if you think they're too drunk? Of course, we have to. They might not know it. Or, you know, we have tricks. Their jack and coke might become a lot of coke, and very little jack. Reporter: It's fine if you get drunk and just pass out? No, it's not okay if you pass out. Something goes wrong in flight, we can't be taking 140 limp noodles by the ankles and pull them off the airplane. A sobering spray that's on the horizon. In the next 5 to 10 years a spray in someone's mouth and you just hold them down and they kind of come to. I'm sorry about that, everyone. Who pulled up my pants? I didn't do that. Reporter: Or worse. Remember gerard depardieu, the inexplicably attractive star of green card? Apparently, after a glass or two, he relieved himself not in the traditional place, but in the aisle of a plane taking off he came clean on the bbc's "graham norton show." Yes, I peed on the plane. Reporter: There you have it. Our next category. The scofflaws of the sky. Cue alex baldwin, kicked off a plane because he wouldn't stop playing words with friends on his phone. And he showed no remorse, appearing on "snl" to basically totally not make an apology. I mean, what harm would it do to let him keep playing a game? A word game for smart people. Reporter: But still, it is little kids, raucous rugrats, who are, by far, the most unpopular class of traveler. Even though -- I really never saw an air rage incident caused by a kid. And I've never seen a drunk and disorderly kid. Reporter: They're joust loud. They need to drive or have a plane for just babies. You know, you want to scream. Go ahead! Get that -- the screamer plane. Reporter: Glozelle is a comedian, an internet star, and frequently furious flier. Get on a plane with kids. And everybody's saying, "oh, we understand. We understand." But I don't. Reporter: So next time I take my kids home to scotland, maybe I should take a boat. Our thanks to nick tonight. Have you survived a nightmare seat mate a passenger who you will never forget? Tweet me. ]
This transcript has been automatically generated and may not be 100% accurate.