All United Airlines flights departing in the U.S. and Canada were briefly suspended Tuesday night, as the airline asked the Federal Aviation Administration to issue a ground stop over an unspecified technological issue.

United, which grounded its flights for about half an hour, said it had “experienced a brief connectivity issue just before midnight Central time on Tuesday, but has since resumed normal operations.”

It was the second time in less than two months that the U.S. airline had requested a halt to its departures over an unspecified technical glitch. In early August, United flights were subjected to ground stop across major U.S. airports including Newark, Denver, Houston and Chicago, which lasted several hours. 

The airline said at the time that it was a “technology issue,” which caused widespread delays throughout its network.

Tucker Reals

Tucker Reals is CBSNews.com’s foreign editor, based in the CBS News London bureau. He has worked for CBS News since 2006, prior to which he worked for The Associated Press in Washington, D.C., and London.

Christmas Day flight delays, cancellations at Chicago airports

After thousands of U.S. flights were canceled or delayed over the holidays in 2022, most holiday travelers this year are off to a cheerier start this Christmas. But a few trouble spots were emerging on Christmas Day.

Roughly 157 flights to, from or within the U.S. had been been cancelled as of 5:25 p.m. Eastern Time, while just 2,058 were delayed, according to tracking service FlightAware.

Airlines had canceled only 1.2% of U.S. flights so far this year as of Dec. 22, the lowest in five years. Nearly 3 million passengers were expected to pass through domestic airports during the busy holiday period, up 16% from 2022.

Southwest flights canceled

Not everyone got off so lucky. Some passengers at Chicago’s Midway International Airport this Christmas Eve were left stranded on Christmas Eve, according to CBS News Chicago, with the U.S. carrier most disrupted during last year’s holiday period — Southwest Airlines — again experiencing problems. Southwest attributed the delays to foggy weather in Chicago, but passengers also told CBS2 that a shortage of workers was a factor.

Those snafus also affected passengers at Denver International Airport, with Southwest canceling 293 flights on Sunday, while nearly 1,300 trips were delayed, FlightAware data shows.

“We had dense fog in Chicago that forced us to discontinue operating last night and into this morning,” Chris Mainz, a Southwest Airlines spokesman, told CBS News Colorado. 

Southwest on Monday canceled 109 flights, or 2% of its daily trips, while 693 flights were delayed, FlightAware data showed. By comparison, Delta and United Airlines canceled eight and six flights, respectively. 

“[Y]ou guys ruined my Christmas two years in a row,” one person posted Friday on X.

Meanwhile, a winter storm in the Northern Plains is bringing snow, ice and riskier road conditions Monday to the region stretching from northern Kansas through Nebraska, the Dakotas and parts of Minnesota, the Weather Channel reported.

Southwest earlier this month agreed to a $140 million settlement with the federal government over the chaos last year that stranded more than 2 million travelers over the holidays. Southwest has previously agreed to pay more than $600 million in refunds and reimbursements to customers.

“This is a message to the entire airline industry: They must take care of passengers, or we’ll use the full extent of our authority to hold them accountable,” Transportation Secretary Pete Buttigieg tweeted on Dec. 18.

—The Associated Press contributed to this report.