Hundreds of United flights across U.S. delayed after "technology issue"

By the numbers: More than 1,000 of United's flights were delayed as of 10:30pm ET — representing about 35% of its scheduled flights, per FlightAware.

Driving the news: "Due to a technology issue, we are holding United mainline flights at their departure airports," United said in a media statement after the outage began at 6:12pm ET.

• Affected airport hubs included Chicago, D.C., Denver, Houston, Newark, New Jersey, and San Francisco, per the FAA.

Zoom in: United said after the tech issue was fixed about 10pm that it expected "residual delays," but its team was "working to restore our normal operations."

• All flights already in the air continued to their destinations and regional express flights were unaffected during the network outage, according to the statement.

What they're saying: Transportation Secretary Sean Duffy said on X Wednesday night that United CEO Scott Kirby had briefed him on the "internal tech outage" and FAA officials were in close contact with the firm's systems operations team to offer support in helping clear up the flight backlog.

• "The issue was specific to United's operations, and is unrelated to the broader air traffic control system," he said.

Between the lines: The airline confirmed the outage was not related to a cyberattack.

• The glitch concerned the Unimatic system, which holds United's flight information including calculations for weight and balance.

Editor's note: This article has been updated with new details throughout.