Khalid Adkins was just trying to get home from the Dominican Republic.

But before the Denver man’s flight left, family members told media and later wrote on a fundraising page, he was sweating profusely and vomited in the bathroom. The airline made him get off, and he went to the hospital, family said.

Loved ones tried to raise $20,000 for a medical evacuation, but Adkins died Tuesday of unknown causes, becoming the ninth U.S. citizen to die in the Dominican Republic this year under circumstances that families are questioning. Now, his family is using the donations to bring his body home.

It was not clear which airline Adkins was flying, and various carriers either did not respond to questions from The Washington Post or said they would not be able to comment for privacy reasons. But the case sheds light on the power that airlines wield to decide who can and cannot fly.

“It’s totally up to the captain onboard the plane,” says Charlie Leocha, president and co-founder of Travelers United, a consumer advocacy organization.

He says travellers face a conundrum: Show up sick and risk not being allowed to fly, or delay a flight because of illness and pay a penalty. He ran into that situation this year when he was diagnosed with pneumonia before a flight back to the United States from Spain. Taking a few extra days would have been so costly that he ended up flying sick.

Travellers who are very sick should still try to change their flight, he says, because airline employees might be able to make an exception to charging extra fees — especially if a passenger shows up in person and looks terrible. Those who want to fly but aren’t allowed should at least try to make sure they won’t be charged extra.

“If they don’t let you get on the plane, then there’s probably a different system, such as they’ll let you go back on a future flight without paying anything extra,” he says.

The World Health Organization says airlines “have the right to refuse to carry passengers with conditions that may worsen, or have serious consequences, during the flight.”

Carriers may need to get clearance from their medical department or an adviser if a passenger’s health could be a hazard to the safety of the plane; would have a negative impact on other passengers or crew; might need medical attention during the flight; or if their condition might be aggravated by the flight, the organization says.

Allen Parmet, a Kansas City physician who served as medical director for TWA, says that although the captain has the authority to decide to refuse to transport someone, most airlines have medical consultants they can call in real time to assess whether someone is too sick to fly.

“The principle is, we don’t transport people who are too sick to travel, because their illness or their condition threatens either their own safety or the health and safety of others,” he says.

Parmet, an aerospace medicine consultant and instructor at the University of Southern California’s Aviation Safety and Security program, says he’s only encountered six or so cases where someone was not allowed to fly because of illness in his 12 years at TWA.

“If you’re a threat to your own health or the health and safety of others, you shouldn’t be on an airplane,” he says. “It’s not an ambulance, it’s a bus.”

Most carriers say travellers with contagious diseases that could be spread to other passengers can be refused; health officials have recently warned people believed to be infected with measles that they could be prevented from getting on a plane. Beyond that, some airlines include a warning about their right to keep someone from flying in case of illness — although they don’t spell out how sick someone must be for that to happen.

In its contract of carriage, for example, American Airlines warns: “If your physical or mental condition is such that in American’s sole opinion, you are rendered or likely to be rendered incapable of comprehending or complying with safety instructions without the assistance of an attendant, American may refuse to transport you.”

Loading... Loading... Loading... Loading... Loading... Loading...

Delta says it can decline to transport or remove passengers who are seriously ill, unless they provide a doctor’s written permission to fly.

While Leocha, the consumer advocate, says he doesn’t hear many cases of sick people being forced off planes, the possibility is real enough that travellers should consider travel insurance with a medical evacuation plan, “because the airlines are not known for being nice about it.”