Washington (CNN) Katie Campos settled into her seat for a short flight from Newark to Buffalo last week. Within minutes, she said, an intoxicated male passenger sitting next to her began groping and harassing both Campos and a second female passenger seated in the same row, grabbing Campos repeatedly despite her demands for him to stop it.

"He grabbed my upper thigh, like in the crotch area, and he grabbed it pretty forcefully," Campos told CNN, adding that the man only stopped touching her after she got out of her seat and ran to the back of the plane, where she told a flight attendant what was happening.

Campos is one of four women CNN interviewed who said they've been sexually assaulted or harassed during a commercial flight. These women are a small fraction of a typically overlooked group enduring inappropriate behavior during an American reckoning with harassment and misconduct that spans across many industries like entertainment, sports, news media and politics.

A police report filed said that the male passenger told the other female passenger seated in Campos' row that he would like to kiss her. When the woman declined, he began stroking her leg. The passenger reported the man's behavior to a flight attendant.

When Campos reported what the man had done to members of the United Airlines crew, she said she didn't feel like she was taken seriously until she said she refused to retake her seat next to him.

"I felt like no one, no one that was supposed to be in charge could handle the situation," she told CNN. "I kept on feeling, and I continue now as I'm like filing these reports, to feel like I'm the one who is doing something wrong, and I'm not being protected."

Ultimately, Campos was reseated -- but directly behind the man who was harassing her. United Airlines told CNN that's because there were few empty seats on the plane. The man, Campos said, didn't stop touching her even after she moved.

"This man continued," she said. "This man should have been restrained so he couldn't continue to do this. And just continuing to touch and stare just made me feel completely helpless and horrible. It was terrifying."

A United Airlines spokesperson told CNN that the airline has "zero tolerance for this type of behavior."

"Our pilot requested that local law enforcement meet the aircraft on arrival," the spokesperson said.

Members of the Niagara Frontier Transportation Authority Police Department met the plane at the gate and escorted the man off the plane, according to the police report. Cell phone video obtained by CNN shows police boarding the flight and removing the man. He has been charged with disorderly conduct.

Campos said the flight crew didn't appear prepared to handle the situation and wondered what could have happened if the relatively short flight had gone on for longer.

"At the end of the day, they didn't protect my safety or those around me," Campos said.

A hidden reality of commercial air travel

It's difficult to determine just how frequently assaults happen on commercial flights because no federal regulatory agency tracks that data nationwide. But FBI investigations into midair sexual assaults have increased by 66% from fiscal year 2014 to 2017. The bureau said it opened 63 investigations into sexual assault on aircraft during the current fiscal year, compared with 57 in 2016, 40 in 2015 and 38 in 2014.

The FBI said it isn't clear what is behind the increase.

Even so, those are just the cases that the FBI investigates, and those figures don't account for incidents reported that the FBI never hears about, or those that are never reported at all like so many cases of sexual harassment overall.

The Association of Flight Attendants-CWA, one of the world's largest flight attendant unions, last year surveyed nearly 2,000 flight attendants about their experiences with midair sexual assaults. Among those who responded, one out of five said they received a report of passenger on passenger sexual assault while working a flight. But, according to the survey, law enforcement was contacted or met the plane less than half of the time. Three of the four women interviewed by CNN about their assault or harassment said there were no apparent attempts to contact law enforcement.

Typically, the AFA said, intervention comes from flight attendants, but many say their employers haven't told them what to do if someone says they've been harassed or assaulted in flight.

Sara Nelson, a United Airlines flight attendant who is president of the union, told CNN, "In my 22 years as a flight attendant, I have never taken part in a conversation -- in training or otherwise -- about how to handle sexual harassment or sexual assault."

While policies exist, Nelson says that if they're not elevated in airlines' training, flight attendants are at a loss of what to do when confronting inappropriate -- and sometimes criminal -- behavior.

"They don't necessarily know exactly what to do and how to respond when they discover it," she said.

Allison Dvaladze said she didn't believe the Delta Air Lines crew knew how to best help her when a man allegedly groped her during a flight. Dvaladze said that as she was dozing off during an April 2016 flight from Seattle to Amsterdam, she felt a hand grabbing her."

I felt a hand in my crotch, and realized that the man next to me was holding, was grabbing my crotch," Dvaladze told CNN. "I slapped his hand right away, yelled 'no,' without even thinking."

The man reached for her again, Dvaladze said, and she again hit him away. After the man reached toward her again, despite her attempts to stop him, she said she unbuckled her seat belt, and ran to the back of the plane where she asked to speak with members of the flight crew.

"I believe they were doing everything they could, in their mind, to comfort me, but it was clear there was not a clear procedure for what they should do," she said. "They asked me what I wanted them to do, and at that moment I really just couldn't think about anything except for wanting to get off the plane."

That wasn't an option in midair. Ultimately, Dvaladze was given a new seat away from the male passenger who had groped her. Dvaladze said she assumed that the crew would file a report based on her experience and she followed up with the airline's customer service department herself about a week after her flight, according to emails reviewed by CNN.

The airline's customer service department responded to her email about a month later, emails show. A representative apologized for her flight experience, saying "I know it's not fair when one person's behavior affects another person."

As a "goodwill gesture," the airline also offered Dvaladze 10,000 frequent flyer miles.

"If somebody reports a crime to an airline, it should be flagged. It should not be treated as if it's lost luggage," Dvaladze told CNN.

A spokesperson for Delta Air Lines told CNN that the airline continues to be "disheartened by the events Ms. Dvaladze described."

The spokesperson said that Delta crew members are "trained to have situational awareness in the cabin at all times and are prepared to handle a range of situations and always prioritize customer safety."

"The lights came on"

CNN reached out to each of the major US airlines, as well as Airlines for America, the industry trade group that represents them. Each responded with a statement with a similar theme: The safety and security of passengers is the priority. Each airline also said that flight attendants are trained to handle incidents like these, but none of the airlines detailed their policies or guidelines.

Alison McAfee, a spokesperson for Airlines for America, said that member airlines "take these matters seriously and do not tolerate harassment in any form."

"Employees receive extensive customer service training to ensure the safety and wellbeing of all our passengers and crew," McAfee said in a statement. "Airlines strive to make sure every passenger has a safe and pleasant travel experience and that disruptive or inappropriate behavior is dealt with as promptly as possible."

McAfee also said that carriers have "well-defined processes and procedures in place" for reporting criminal activity to the Federal Aviation Administration and the appropriate law enforcement authorities.

Each of the women CNN spoke to who said they were sexually harassed or assaulted during a commercial flight said the flight crews did little or nothing to help. Ayanna Hart was a passenger on a Delta Air Lines flight. She said an intoxicated man repeatedly grabbed her during a flight earlier this year and said a flight crew member was dismissive of her concerns.

The last time the male passenger grabbed her, Hart said the flight attendant told the man, "oh, no touching." When another passenger called the flight attendant over to express concerns about the man, the flight attendant was of little help.

"The flight attendant said, 'Oh, don't worry about him. He flies with us all the time. He's Delta Platinum,'" Hart said, a reference to the top tier of Delta's frequent flyer program.

Now, Hart is suing Delta for failing to intervene and continuing to serve the man alcohol.

The airline wouldn't comment on the case, citing pending litigation, but said it takes these incidents "seriously" and "with law enforcement, investigates them."

The Association of Flight Attendants-CWA has called on airlines to do more not just to train crew members on how to handle sexual assault and harassment that has happened to passengers in the air, but also to do more to protect the crew members themselves.

"Not only are we not equipped with good, clear policies about how to do that and training about how to do that, you're asking people who are experiencing sexual harassment every single day to now be the enforcers and it just doesn't make a lot of sense," said Nelson, the head of the AFA.

The situation is equally senseless for passengers who have experienced harassment and who say they are left with little comfort.

Campos, the United Airlines passenger who said she endured repeated groping and unwanted touching at the hands of a man seated next to her, said she felt that even the people who were supposed to ensure her safety on board the late-night flight were unable to do so.

"It felt very much like the only reason this came to an end at all is that the flight landed. And we were at a gate, and the lights came on," she told CNN.