Nearly 1,800 American Airlines flights have been canceled since Friday. American Airlines blamed "additional weather" and "tight" staffing for a quarter of all their flights canceled this weekend.
FlightAware, a flight tracking site, said there were 376 American Airlines canceled on Friday, 543 on Saturday, and another 877 canceled by Sunday afternoon. American Airlines has also delayed over 1,000 flights since Friday.
American Airlines issued a statement to CNN to try to explain the massive number of cancellations.
"With additional weather throughout the system, our staffing begins to run tight as crew members end up out of their regular flight sequences," American Airlines said.
The airline claimed that two days of severe winds at the Dallas/Fort Worth International Airport — American Airlines' largest hub — reduced the arrival capacity because the carrier "could only use two runways instead of the usual five."
However, Southwest Airlines had 87 cancelations on Saturday, United Airlines had 18, and Delta Airlines only had two, according to data from FlightAware.
David Seymour, American's chief operating officer, sent a memo on Saturday to inform employees that the weekend "will be challenging," according to Fox Business.
The majority of American Airlines' Saturday cancellations were caused by a lack of available crew members, especially flight attendants, the Wall Street Journal reported.
American doesn't expect the issues to persist past the weekend. The airline noted that 1,800 flight attendants would be returning from leave starting on Nov. 1, and over 600 new hires would be employed by the end of December.
Southwest Airlines experienced a similar mass cancellation event earlier this month. Southwest blamed "disruptive weather" and air traffic control issues for the cancellation of nearly 2,000 flights in one weekend. There was speculation that the mass cancelations were caused by a "sickout" or protest over COVID-19 vaccine mandates.
Days after the mass cancellation event that cost Southwest $75 million, the airline reportedly scrapped a plan to place unvaccinated employees, who don't have an exemption, on unpaid leave.
President Joe Biden signed an order that requires federal contractors to ensure their employees are fully vaccinated by Dec. 8 — including American Airlines — unless employees are exempt for medical or religious reasons.
American Airlines CEO Doug Parker said the overwhelming majority of the carrier's employees are vaccinated. He added that a small minority "almost certainly" will have a religious or medical exemption by the deadline "and those who aren't we'll continue to work with," according to CNBC.