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EXPLAINER: Why are so many flights being canceled?

Jessica Andrijauskas, from Buenos Aires, rests her head on her luggage as she awaits the results of her COVID-19 test, at Ronald Reagan Washington National Airport, Wednesday, Dec. 29, 2021, in Arlington, Va. Winter weather and crew members infected with COVID-19 have forced airlines to spike thousands of U.S. flights over the past week, complicating travel plans for many people during the busy holiday season. It's not clear when travel will return to normal, but airlines say a recent move by U.S. public health officials should help get workers back sooner. (AP Photo/Alex Brandon) Jessica Andrijauskas, from Buenos Aires, rests her head on her luggage as she awaits the results of her COVID-19 test, at Ronald Reagan Washington National Airport, Wednesday, Dec. 29, 2021, in Arlington, Va. Winter weather and crew members infected with COVID-19 have forced airlines to spike thousands of U.S. flights over the past week, complicating travel plans for many people during the busy holiday season. It's not clear when travel will return to normal, but airlines say a recent move by U.S. public health officials should help get workers back sooner. (AP Photo/Alex Brandon)

By TALI ARBEL and PAUL WISEMAN / Associated Press December 30, 2021 7 min read

The forces that have scrambled thousands of flights since Christmas Eve could ease in January, but that’s cold comfort to the millions of flyers with New Year’s plans.

And if 2021 has taught us anything, it’s that 2022 will likely be just as unpredictable.

Here’s a look at what has mucked up flights for thousands of people this holiday season, and what could happen over the next few weeks.

WHAT HAPPENED?

Airlines weren’t spared from the spread of the omicron variant, which knocked out flight crews at airlines that had already reduced the size of their workforces following the collapse of air travel in 2020.