Alaska Airlines, Southwest, United, American, Alaska Air—Major Airlines Experiencing Technical Issues

Major airlines in the United States were hit by systemwide computer outages on April 1, the Federal Aviation Administration said.

The agency said the outages stemmed from problems with the Aerodata planning weight and balance program.

Carriers reported problems through their social media accounts: United Airlines said it was unable to create paperwork; American Airlines, the top carrier in the country, said the outage was affecting regional carriers nationwide; Delta Air Lines later said it was affected by the issue; and Canada’s Alaska Air Group said it was experiencing a systemwide outage.

Southwest Airlines reported problems as well but later said on Twitter that it had received word that the problem had already been resolved and that systems would be back up soon. American soon confirmed that the technical issue had been resolved.

“It looks like things are up and running again, but we appreciate your patience!” the official Southwest account told a customer. Earlier, it had apologized to people and said it was working on solving the issues.

“Our Employees have been working around the clock to get you on your way, Carl. We appreciate you hanging in there with us,” it told one user.

“The technical issue that impacted a few of our regional carriers has been resolved. We apologize to our customers for the inconvenience,” American added shortly after 8 a.m. EDT.

Passengers were waiting on Monday morning, April 1, at airports nationwide as airlines rushed to deal with the problems.

NBC News producer Brian Alkire said he was among those stranded after a ground stop for his Southwest flight. “Pilot called it a ‘3rd-party computer server outage,'” Alkire wrote.

Delta passengers also complained of delays and Delta later said the problem was no longer affecting its servers.

“The issue prevented some Delta Connection flights from being dispatched on time this morning has been resolved,” its official Twitter account stated.

Alaska Airlines, also affected by the technical issue, had not said the issue was solved as of 8:21 a.m. EDT, nor had Alaska Air Group.

Reuters contributed to this report.