(NEW YORK) -- As pre-pandemic level crowds hit the airports for the holidays, three major U.S. airlines have been forced to proactively cancel more than 300 Christmas Eve flights due to the fast-spreading omicron variant of COVID-19.
United Airlines has cancelled 169 flights for Christmas Eve, as of Friday morning.
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"The nationwide spike in omicron cases this week has had a direct impact on our flight crews and the people who run our operation," United said in a statement. "As a result, we've unfortunately had to cancel some flights and are notifying impacted customers in advance of them coming to the airport."
"We're sorry for the disruption and are working hard to rebook as many people as possible and get them on their way for the holidays," the airline added.
A United Airlines airplane is pushed back from its gate at Newark Liberty International Ai...Read More
And it's not just United that's feeling the impact of the variant on crews.
Delta Air Lines has cancelled 124 flights for Christmas Eve. The airline says the "flight cancellations are due to a combination of issues, including but not limited to, potential inclement weather in some areas and the impact of the omicron variant."
"Delta teams have exhausted all options and resources -- including rerouting and substitutions of aircraft and crews to cover scheduled flying -- before canceling around 90 flights for Friday," Delta said in a statement to ABC News. "We apologize to our customers for the delay in their holiday travel plans. Delta people are working hard to get them to where they need to be as quickly and as safely as possible on the next available flight."
Alaska Airlines has resorted to offering extra pay to their healthy employees who can work added shifts into this upcoming Christmas weekend.
The airline says they have had to cancel 10 Christmas Eve flights due to some of their employees quarantining after reporting that they may have been exposed to COVID-19.
Airlines for America (A4A), the group that lobbies on behalf of all major U.S. airlines, is calling on the Centers for Disease Control and Prevention to shorten the quarantine time for fully vaccinated individuals, saying the omicron surge may create "significant" disruptions.
People wait in line to check in at the United Airlines ticket counter at Hartsfield-Jackson...Read More
"The omicron surge may exacerbate personnel shortages and create significant disruptions to our workforce and operations," Nick Calio, A4A's CEO, said in a letter on Thursday to CDC Director Rochelle Walensky.
Calio proposed the isolation period to be shortened to five days from symptom onset for breakthrough infections.
"In turn, those individuals would be able to end isolation with an appropriate testing protocol," Calio wrote.
The letter comes after Delta Air Lines and JetBlue Airways, both A4A members, also asked for isolation periods for fully vaccinated individuals to be shortened.