As air travel has ticked up in the last month, airlines have divided into two camps: those blocking strategic seats to offer more space, and those willing to fill planes to capacity.

In the latter camp, United Airlines never instituted limits and continues to sell all available seats as demand allows. As of July 1, American Airlines announced it would drop its capacity restraints, in place at 85% since April.

In the other corner are Alaska Airlines, Delta Air Lines and Southwest Airlines who say they will continue to block middle or adjacent seats through Sept. 30. JetBlue Airways just extended its ban on selling middle seats through Labor Day.

The rise of full flights this summer has enraged some travelers. In response to a recent New York Times story on the lack of social distancing in the air, one reader commented, “I recently flew on two different American Airlines flights. Passengers totally packed together as in the old days, zero social distancing, and frequently, the stewardess left her mask hanging off her face. NEVER again.”

Airlines that are leaving key seats open say the measure is designed to reassure the public of their safety in the air. “We’re adding tens of thousands of flights to address extra demand while leaning in on that assurance of distancing,” wrote Brad Hawkins, a spokesman for Southwest, in an email.

“More space matters, and more space is better for you,” said Drake Castaneda, a spokesman for Delta.

The economic pressure to sell all seats is enormous. Last week, Delta announced that its revenue plunged 88% in the second quarter, losing $5.7 billion. Also last week, American said it could furlough 20,000 people beginning Oct. 1, when federal stimulus funds expire. United said it could shed 36,000 jobs in the fall.

“Whatever airlines do to make people comfortable flying again is good for the entire industry,” said Seth Kaplan, an airline expert and host of the podcast Airlines Confidential. “United and American are probably glad Delta and Southwest are giving the public confidence in flying, but they’re going to take the money.”

Among these four biggest airlines in the nation, he added, Delta and Southwest entered the pandemic in a stronger financial position than American and United.

As of mid-July, the average flight only carries about 60 people, flying at an average of about 50% capacity, according to the trade group Airlines for America, making it easier for the more generous airlines to guarantee open space.

Rather than blocking seats, American and United are offering rebooking for travelers on crowded flights through preflight notifications, though some fliers have complained that changing plans at the last minute is inconvenient. Joy Gonzalez of Seattle, a recent flier on American, said the options she’d been given to change involved long trips “with two or three layovers.”

“We have multiple layers of protection in place for those who fly with us, including required face coverings, enhanced cleaning procedures and a preflight COVID-19 symptom checklist — and we’re providing additional flexibility for customers to change their travel plans, as well,” wrote Ross Feinstein, an American spokesman, in an email.

A United spokesman, Charles Hobart, wrote in an email that “the overwhelming majority of our flights continue to depart with multiple empty seats.”

On airlines that aren’t blocking seats, carriers say they allow passengers, once boarded, to move to an empty seat within their ticketed cabin, even if that seat is a premium seat, assuming there isn’t an issue with balance and weight distribution.

Banning middle seats?

Just hoping for an empty seat isn’t enough for Sen. Jeff Merkley, D-Ore., who tweeted about his packed American Airlines plane from Dallas to Portland, Ore., on July 2, concluding, “No way you aren’t facilitating spread of COVID infections.”

The next day he wrote on Twitter that he would “introduce a bill to ban the sale of middle seats through this pandemic.”

“I recognize this does not fill the 6-foot standard established by the CDC,” he said in an interview. “But it’s the minimum requirement to decrease substantially the immediate proximity of someone else’s exhaled breath.”

Even if middle seats are left open, experts point out that you’re still not going to get the desired 6 feet of safe distance from the passenger occupying the same row. Still, some medical experts say travel can be done safely.

“Shorter is better, in terms of flights, so you don’t have as much exposure to other people,” said Preeti Malani, chief health officer and a professor of medicine in the infectious diseases division at the University of Michigan.

“I tend to feel window seats are better because you’re around fewer people,” she added.

Airlines have also increased aircraft cleaning frequency and strengthened their sanitation protocols. They also point to their strong air filters — most use high-efficiency particulate air or HEPA filters that remove over 99% of airborne particles — and the constant circulation of fresh air in the cabin in mitigating virus spread.

In its advice to travelers, the CDC states on its website, “Most viruses and other germs do not spread easily on flights because of how air circulates and is filtered on airplanes.”

Mask up on flights

More important than social distancing, experts say, is wearing a mask.

“A lot of people are asymptomatic with this, which is why we really want everyone wearing masks,” said Dr. Trish Perl, chief of the Division of Infectious Diseases at the University of Texas Southwestern Medical Center, in a recent news conference on behalf of the Infectious Diseases Society of America. She noted that masks reduce the risk of catching the virus by up to 70%.

Most airlines in the United States require masks except when a passenger is eating or drinking, which has sparked some dissent in the air. In June, CNN reported that one passenger had been removed from an American flight for not wearing a mask and banned from future flights while the mask mandate is in place.

“It’s been a patchwork since there is no federal mandate on masks,” said Sara Nelson, president of the Association of Flight Attendants union, which is calling on government leadership to normalize face coverings in flight the same way the Federal Aviation Administration mandates seat belts for safety.

“Once that’s communicated, people are used to following the rules, especially in aviation,” she added. “You have to recognize, this is not a normal day. When you’re flying, your fate is tied up with others.”

Stimulating travel safely is important to the nation’s economic recovery, according to the U.S. Travel Association, which says the industry is in a depression with 51% unemployment. It forecasts that travel spending will decline $519 billion this year because of the pandemic.

But recovery, reliant on consumer confidence, might, in part, depend on the feeling of safety offered by providing extra elbow room in the air.

“We have decided as a nation that airlines are essential,” said Merkley. “In every essential setting, we’ve asked businesses to make accommodations to minimize the transmission of the virus. In stores, we have masks and sometimes one-way aisles. In restaurants, we have tables further apart. It’s reasonable to ask airlines to do the maximum they can, like not selling adjacent seats.”

© 2020 The New York Times Company