Numerous flights were canceled in the United States on Monday as the spread of the Omicron variant has left major US airlines on staff for several days.
According to FlightAware, which tracks flight cancellations, airlines have canceled about 4,000 flights to, from or within the United States since Friday, including about 1,000 on Monday.
Delta, United, JetBlue and American have all said the coronavirus is causing staff problems, and airlines in Europe and Australia have also canceled holiday flights because employees were infected.
However, the weather and other factors also played a role. Winter weather conditions in the Pacific Northwest led to nearly 250 cancellations of flights to or from Seattle on Sunday, Alaska Airlines said, and the airline expected more than 100 flight cancellations on Monday. COVID-19 is no longer a factor, the company said.
United said it canceled 115 flights on Monday, out of more than 4,000 scheduled, due to crews sick with COVID-19.
Flight delays and cancellations linked to staff shortages have been a constant problem this year. Airlines urged workers to quit in 2020 when airline sales plummeted, and have been short-staffed this year as the industry rebounded faster than expected.
Airlines have called on the Biden government to review the guidelines to shorten the isolation period for vaccinated workers who are infected with COVID-19, in a bid to alleviate staff shortages. The flight attendants union opposed the move, saying the isolation period should remain for ten days.