Flight delays have affected US airlines; Computer problems blamed: NPR

Updated at 12:09 ET

Thousands of travelers on some of the largest US airlines had to wait a long time Monday morning, as their flights were delayed due to a computer problem faced by a contractor. The technical problem forced Southwest Airlines, which was among the biggest problems, to stop all US flights for about 40 minutes Monday.

"At 9:00 am Eastern Time, more than 600 Southwest flights were delayed," said David Schaper, of NPR. United said nearly 150 flights with its regional carriers had been affected, and American and Delta also said that about 20 flights provided by its regional carriers had been affected.

The delay hit the southwest shortly after 7 pm, forcing the ground stop which lasted until 7:45 am. The FAA announced at 8:30 that the "problem had been solved". But at that time, the delays were already rising.

"Several US airlines are facing IT problems this morning," the Federal Aviation Administration said on Twitter, asking passengers to check the status of their flights with their airlines. The agency reminded readers – some of whom, no doubt, frustrated passengers whose planes had not taken off – that it did not control flight cancellations.

Southwest said that it was a computer failure of a third-party vendor that had affected "the data used in flight planning".

This provider is AeroData, a company that allows airlines to plan the weight and balance of their aircraft for security reasons, as well as other flight planning systems, said Southwest in an email to NPR .

AeroData customers include Southwest, American, Delta, United and JetBlue – all airlines reporting delays on Monday.

The AeroData system "is the latest application used by pilots before closing the aircraft's front door before takeoff," according to a company profile established in 2017 by the VMware data management company. "As a result, only five minutes of system downtime can result in more than 100 delayed flights and lost revenue."

Significant delays were reported Monday at several airports, from Phoenix to New Orleans and from Atlanta to New York and Chicago, according to Flightradar24. For the affected airlines, the first disruptions affected their flights on Monday morning.

When they apologized to the travelers, the carriers also said the situation was out of their control.

"The AeroData system is coming back slowly," American Airlines said via Twitter, adding that new departure delays would probably be needed on Monday.

Technical issues have added to weather related safety concerns in a number of airports; the FAA said that high winds could also cause delays in Boston, Chicago, New York and Philadelphia.