HOUSTON — Southwest Airlines canceled hundreds more flights Monday following a weekend of major service disruptions.
According to Flightaware, the carrier has cancelled 348 flights Monday and delayed another 303 flights.
The Dallas-based airline had blamed air traffic control issues and weather for its weekend “operational challenges” that saw over 1,000 cancelled flights on Sunday alone.
Southwest Airlines was the only airline to report the issues on that scale.
Weekend flight cancellations
Southwest Airlines customers at Houston airports and across the country are experiencing a large number of cancellations this weekend.
The airline said in a Facebook post that due to air traffic control issues and disruptive weather that a large number of flights would be canceled across the U.S.
Some passengers said they were told the airline's COVID-19 vaccine mandate is to blame for a massive walkout, which led to the cancellations.
Customers who were affected by cancelations were asked to rebook their flights by visiting Southwest's website.
Houston Airports reported at least 136 Southwest flights were canceled at Hobby Airport over the weekend, including 86 flights on Sunday, according to Flight Aware.
Southwest had five cancelations at George Bush Intercontinental Airport on Sunday.
Southwest canceled almost 2,000 flights nationwide, or 28% of its schedule, as of 1 p.m Sunday, according to flight tracker FlightAware.
The cancellations mark the highest rate by far of other major U.S. airlines.
The next in line are Allegiant and Spirit, both of which have canceled 5% and 4% of their flights, respectively, on Sunday, according to the flight tracker. American Airlines canceled 2% of its flights.
The nationwide cancellations came as the airline announced Monday that the company will now require employees to get the COVID-19 vaccinated by Dec. 8.
Some customers said they were told the cancellations are a direct result of the vaccine mandate.
“I asked them specifically 'is this about weather' – because if it’s about weather, they can deny compensation. They said 'no, it’s not about weather.' I said 'is this about maintenance?' They said 'no, it’s not about maintenance.' I said then 'what is the problem?'" passenger Ron Frank said. “They said this is all because of the vaccine mandate. They said we had a massive walkout. They also said that air traffic control had a massive walkout because of the vaccine mandate. But to couch 1,000 cancelations because of a thunderstorm somewhere is not believable.”
Southwest Airlines statement
"We experienced weather challenges in our Florida airports at the beginning of the weekend, challenges that were compounded by unexpected air traffic control issues in the same region, triggering delays and prompting significant cancellations for us beginning Friday evening. We’ve continued diligent work throughout the weekend to reset our operation with a focus on getting aircraft and Crews repositioned to take care of our Customers.
"With fewer frequencies between cities in our current schedule, recovering during operational challenges is more difficult and prolonged.
"We’re working diligently to accommodate our Customers as quickly as possible, and we are grateful for their patience. We’re offering Customers added flexibility to explore self-service rebooking options on Southwest.com, where they can get updates on the status of their travel. We know the frustration flight cancellations are creating for our Customers and Employees and we apologize, and we again thank everyone for patience as we work first to be safe, and second to be as quick as possible in solving disrupted plans."
Pilots union statement
"SWAPA is aware of operational difficulties affecting Southwest Airlines today due to a number of issues, but we can say with confidence that our Pilots are not participating in any official or unofficial job actions," the press release said.
Southwest Airlines is the only airline experiencing a high volume of cancelations.
Editor's Note: The 9NEWS team in Denver wrote the original article, which was posted here.