Protecting air travelers and aviation workers from the coronavirus is a challenge unlike any other. Yet, so far, it's unclear which government authority would take responsibility for passenger health precautions.
Airlines are putting together a patchwork of polices for flying during the pandemic, such as blocking off middle seats, issuing new boarding procedures and requiring masks. At least one airport has started using a thermal camera to screen people for fevers.
On Tuesday, Sens. Ed Markey, D-Mass. and Richard Blumenthal, D-Conn., introduced a bill that would instruct several health agencies to set up a task force to establish plans and guidelines related to flying. The task force would also set protocols for a recovery in air travel demand, which is down more than 90% on the year.
But a specific government plan has yet to materialize that would standardize tasks like performing health screenings on passengers, mandate masks or require other precautionary measures to inhibit the spread of Covid-19 in what has long been the world's biggest aviation market.
"It's going to be a game of hot potato," said Jeffrey Price, an air travel safety expert and a professor at Metropolitan State University of Denver.
Last week, the aviation arm of the United Nations launched a task force that includes the World Health Organization, and more than a dozen governments, aviation regulators and industry groups to address needed changes to air travel.
One of the big questions regarding passenger health checks is where the screening can be conducted.
"To think that you're going to put people in an enclosed space and crowd them up, you're going to put them more at risk than if you did nothing at all," said Angela Gittens, director general of the Airports Council International, an airport trade group. "You want to take measures that are aligned to the risk."
The Department of Homeland Security units that are tasked for screening outbound passengers and incoming arrivals — the Transportation Security Administration and Customs and Border Protection, respectively — are relying on health expertise from the Department of Health and Human Services and the Centers for Disease Control and Prevention, the DHS said.
"DHS will continue to have ongoing discussions with interagency colleagues, as well as our airport and airline partners to make informed decisions with regard to the health and safety of the aviation environment," the agency said in a statement.
The CDC has discussed health precautions with flight attendant unions and the Department of Transportation, among others. Labor unions, including the Association of Flight Attendants, the country's largest flight attendant union, have urged federal agencies to mandate masks for employees and travelers and require crew have access to gloves and alcohol-based gels.
The CDC recommends people wear cloth face coverings over their nose and mouths "when in a community setting, including during travel if they must travel." The masks are "not intended to protect the wearer but may prevent the spread of virus from the wearer to others. This is especially important in the event that someone is infected but does not have symptoms," the CDC said in a statement.
But CDC spokesman Bert Kelly said the agency does not carry out enforcement. "We do not mandate issues. We make recommendations," he said.
Last week, Rep. Peter DeFazio, D-Ore., chairman of the House Committee on Transportation and Infrastructure, urged Federal Aviation Administration chief Steve Dickson to require masks or face coverings for all crew and passengers and to mandate more space between passengers.
"As our Nation confronts this devastating public health crisis, it is incumbent on every Federal agency to provide clear, consistent requirements that put the health and well-being of all Americans first," DeFazio said in a statement. "I believe these measures are not only well within the FAA's jurisdiction, but are also essential to protect frontline airline employees as well as the members of the flying public who still must travel during the pandemic."
The Air Line Pilots Association, which represents pilots at United, Delta and others, asked the Department of Transportation in late March to mandate cleaning standards for aircraft and to require airlines to notify employees when co-workers whom they've been in contact with recently test positive for Covid-19.
In an April 14 response letter to the Air Line Pilot Association, Dickson said: "While the FAA remains steadfast in its focus on safety of flight, we are not a public health agency. We must look to other U.S. Government agencies for guidance on public and occupational health."
The FAA told CNBC in a statement last week that the agency is "working with air carriers to ensure they have processes in place for addressing public health risks for their crews and passengers."
The union that represents some 46,000 Transportation Security Administration officers, the American Federation of Government Employees, has urged Congress to ensure that TSA workers have enough protective equipment and warned that they face "substantial exposure" to the disease. Some 500 TSA officers have tested positive for Covid-19, it said.
Sydney Glass, a union spokeswoman, balked at the idea of TSA officers potentially conducting health screenings of passengers, telling CNBC: "Requiring TSA officers to conduct Covid-19 testing is far from their duties and responsibilities."
The union is pushing for a requirement that passengers wear masks when they enter airport security checkpoints.
The TSA, which was established two months after the Sept. 11, 2001 terror attacks, is tasked with screening passengers and baggage for prohibited items. Adding health checks to screen for what is essentially an invisible threat could be detrimental, MSU's Price warned.
"If I'm a TSA officer I have to look for guns, knives, bombs and now you want me to do health checks? " he said. "I can only do so many well at once."
Airlines have started putting their own measures in place on planes to reassure travelers. For example, major airlines said last week they will start requiring passengers — as well as flight attendants and some other employees — to wear masks. Some carriers, including American, said they will make masks available for travelers.
In addition to masks, American tplans to start distributing sanitizing wipes and or gels this month. Leisure carrier Allegiant said it will provide passengers single-use masks, disposable latex gloves and cleaning wipes as they board.
Airport Council International's Gittens said one thing that might change is passenger interaction with touchscreens at airports.
United Airlines said it's planning to test touchless kiosks where travelers print luggage tags. It has also started boarding planes back to front to avoid crowding and is having travelers scan their own boarding passes.
President Donald Trump, after he was asked last week about travel from Latin America, said the administration is "setting up a system where we do some testing, and we're working with the airlines on that," referring to both temperature checks and virus tests.
The White House didn't comment beyond Trump's statements. Industry members say the government would be responsible for any health screenings.
Airlines for America, an industry group whose members include Delta, American, Southwest, United and JetBlue, said "all screening processes for the traveling public are the responsibility of the government" in the U.S.
"U.S. airlines have been taking substantial, proactive steps to protect passengers and employees throughout this crisis. A4A's member carriers all comply with or exceed all CDC guidance," it said.
American Airlines CEO Doug Parker said last week that its employees shouldn't conduct health tests.
"We would certainly view that as a role that should be provided by the government and health service providers, not airline employees," he said.