Airlines have been left short by sick staff calling in sick due to COVID-19, especially since the introduction of the Omnicron variant. FlightAware tracks cancellations and shows that airlines have cancelled approximately 4,000 flights between the U.S. and Canada since Friday.
American, United, JetBlue, and Delta all stated that coronavirus was causing problems for staff. European and Australian airlines cancelled holiday-season flights due to staff infected. However, weather and other factors also played a part.
United announced Monday that it had cancelled 115 of the more than 4,000 flights scheduled by the airline due to COVID-19 crews.
This year, flight delays and cancellations due to staff shortages have been a constant problem. When air travel collapsed in 2020, airlines encouraged employees to leave. However, they were caught short of staff this year because air travel recovered faster than anyone expected.
Biden administration has been asked by airlines to reduce the time for isolation for COVID-19-vaccinated workers. This is to help with staff shortages. The union representing flight attendants resisted this, stating that the isolation period should be maintained at 10 days.