Airlines like American and United don't have concrete plans to ensure social distancing as passengers return to crowded flights

• The number of travelers passing through TSA checkpoints has increased steadily for five days, reaching its highest point since April 3.
• The increase is small compared to normal passenger levels, but with airlines cutting capacity due to the coronavirus pandemic, a continued increase in passengers could mean more crowded flights.
• Crowding creates a difficult situation for airlines, which need to assure their larger customer base that air travel is safe in order to recover from the worst financial crisis the industry has ever faced. Options include taking steps to encourage social distancing or requiring face masks, among other options.
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The number of Americans boarding commercial flights has risen steadily over the past five days, leading to an increase in reports of crowded flights on which social-distancing measures were impossible.

According to the Transportation Security Administration, the number of daily travelers passing through security checkpoints at commercial airports has climbed from 92,859 on Tuesday, April 21, to 128,875 on Sunday, April 26. The Sunday number was the highest since April 3.

The TSA numbers offer a virtual real-time look at travel demand and trends in the US as the coronavirus continues to inflict damage on the airline industry. During the same period in 2019, an average of more than 2 million daily travelers regularly passed through security checkpoints.

Airlines around the world have significantly reduced their capacity over the past two months as the coronavirus pandemic has led to plummeting travel demand. Many have suspended routes, canceled flights or frequencies, and grounded large portions of their fleets.

Demand remains low, including for future travel — airlines have reported virtually zero incoming revenue, which has led to flights operating just 5% to 10% full. The major US airlines have reduced their capacity 80% to 90% for May and June.

The reduced capacity, however, means that even a slight uptick in passengers could be significant, particularly as federal and state guidelines continue to stress maintaining social distancing as a way to slow the spread of the virus.

On an American Airlines flight last week from Miami to New York's LaGuardia, which was 80% to 90% full, according to a passenger on board, only about half of the passengers wore masks.

Sara Nelson, president of the Association of Flight Attendants-CWA, which represents flight attendants at about 20 airlines, said that the same thing has occurred on numerous flights over the past week.

Nelson posted a photo of a flight this weekend on Twitter, which showed a plane crowded with passengers not wearing masks. Nelson and the AFA have called for the Department of Transportation to require passengers to wear face coverings, and to prohibit non-essential travel until the spread of the virus can be contained.

Although several airlines have measures in place to facilitate social distancing, it was not clear how sustainable or effective they would be.

According to the Centers for Disease Control and Prevention, wearing masks or other face coverings may help prevent carriers of the virus from spreading it to others in close proximity, but maintaining at least six feet of distance between people is more effective.

Canada has required airline passengers and crews to wear face coverings in airports and on airplanes, but the US does not have similar regulations, and several of the anecdotes in recent days suggest that social-distancing practices are not always being facilitated or followed.

Delta has said it would block middle seats on its flights, and would prevent upgrades from being automatically assigned so that passengers would not end up seated directly next ot each other.

Although American Airlines also blocks some seats on flights, including middle seats and those adjacent to flight-attendant jump seats, the airline will assign those seats if the flight is nearing capacity, rather than bumping passengers, according to an internal document seen by Business Insider.

A spokesperson for American said that the airline is in close contact with the CDC and has been diligent about cleaning and disinfecting planes throughout the outbreak, and noted that the CDC does not require masks for passengers.

"Last month, in response to CDC social distancing guidelines, American began temporarily relaxed seating policies for customers on our flights and reduced onboard food and beverage service levels," the spokesperson said. "To encourage social distancing, gate agents will reassign seats to create more space between customers."

"American now also blocks 50% of standard middle seats and all seats adjacent to Flight Attendant jump seats on every flight across our system," the spokesperson added. "Our team also monitors flights closely to maintain social distancing."

United, meanwhile is blocking passengers from selecting certain seats to avoid people sitting directly next to each other — however, the airline will still assign those seats if a flight is relatively full.

Southwest, which does not assign seats on its flights, said that flight attendants were encouraging passengers to select seats spaced away from each other when possible.