New CDC isolation guidance may ease COVID-related flight cancellations

U.S. airlines and travelers got their first sign of possible relief from the dayslong crush of canceled flights on Monday when the Centers for Disease Control and Prevention changed its COVID-19 isolation guidelines.

Since Christmas Eve, more than 5,000 flights with at least one stop in the U.S. have been canceled, according to FlightAware. As of 11 a.m. Tuesday morning, more than 850 U.S. flights had been canceled for the day. The disruptions have been partly caused by the surge in COVID-19 cases among critical flight personnel such as pilots, flight attendants and baggage handlers.

But there's some fresh hope for airline industry now that the CDC has shortened the isolation period for asymptomatic and fully vaccinated individuals who contract COVID-19 from 10 days to five.

"The new CDC guidelines should be helpful to airlines and travelers," aviation expert Henry Harteveldt told ABC News. "The shorter isolation time will allow asymptomatic employees to return to work sooner, increasing the number of crew members available to work, and reducing the risk that flights will have to be canceled."

Airlines had been asking for the shortened isolation period for almost a week, warning that omicron could wreak havoc on air travel in a letter to CDC Director Rochelle Walensky on Thursday.

"We appreciate the CDC’s announcement updating isolation guidelines," Airlines for America, the group that lobbies on behalf of the major U.S. airlines told ABC News. "The decision is the right one based upon science."

Delta Air Lines, which was the first airline to ask the CDC to shorten the isolation period to five days, says it is already working to implement the new guidance.

"The updated guidance allows more flexibility for Delta to schedule crews and employees to support a busy holiday travel season and a sustained return to travel by customers," the airline said in a statement.

But experts warn there are still some specifics on return to work protocols that need to be worked out between the CDC and Federal Aviation Administration.

"The CDC states that workers who are asymptomatic must wear a mask while around other people in public," Harteveldt explained. "However, current FAA regulations make it optional for pilots to wear masks in the cockpit. If a pilot believes that wearing a mask interferes with her or his work duties, such as communicating with another pilot or with air traffic controllers, she or he doesn’t have to wear a mask. Airline management, their unions and the CDC need to collectively discuss the conflict that exists between the new CDC policy and current 'optional mask' policy for pilots."

And those who represent aviation workers on the front lines worry that the new guidance is putting profit over safety.

"We said we wanted to hear from medical professionals on the best guidance for quarantine, not from corporate America advocating for a shortened period due to staffing shortages," President of the Association of Flight Attendants Sara Nelson said shortly after the CDC's announcement. "The CDC gave a medical explanation about why the agency has decided to reduce the quarantine requirements from 10 to five days, but the fact that it aligns with the number of days pushed by corporate America is less than reassuring."

The updated isolation guidelines come as the winter holiday travel rush continues.

Air travel is beginning to pick up again before New Year's Eve with another 2 million passing through U.S. checkpoints on Monday. The Transportation Security Administration estimates another 14.5 million will be screened at U.S. checkpoints from now until Jan. 3.