United Airlines Grounds Flights Nationwide Due to Glitch
United Airlines grounded all of its mainline flights across the United States on Wednesday night after a critical technology failure disrupted its weight and balance computer system—an essential component of flight operations.
The widespread disruption began around 8 p.m. EDT, when reports of technical issues flooded outage-tracking websites like DownDetector. United soon confirmed the problem, announcing it was halting all mainline departures as it worked to resolve the issue.
“Due to a technology issue, we are holding United mainline flights at their departure airports,” the airline said in a statement to ABC News. “We expect additional flight delays this evening as we work through this issue. Safety is our top priority, and we’ll work with our customers to get them to their destinations.”
The airline emphasized that this was not the result of a cyberattack.
Flights already in the air were allowed to continue to their destinations, and regional flights operated by United Express were not impacted by the ground stop. However, major airport hubs—including Newark Liberty, Chicago O’Hare, Denver International, Houston Bush Intercontinental, and San Francisco International—experienced widespread disruption as hundreds of aircraft were held on the ground.
The Federal Aviation Administration (FAA) confirmed that United Airlines had requested a nationwide ground stop due to the outage, according to Reuters.
As of late Wednesday evening, the flight-tracking service FlightAware reported over 800 delayed United flights and at least 23 cancellations.
Frustrated travelers quickly turned to social media to document their experiences. Many shared photos of crowded gates and empty tarmacs, with some passengers stuck onboard planes without clear updates. One user posted, “System-wide outage, all United Airlines planes grounded. Sitting on the plane… they have given us the option to get off with no ETA.”
United responded to many of these posts on X, formerly Twitter, stating, “We’re aware of the system error at this time and are working on a fix to have you on your way as soon as possible. We understand that this disruption has caused frustrations during your travel and appreciate your continued patience.”
By late evening, United reported that systems were beginning to come back online, but warned that delays would likely continue through the night.
The airline has not yet released further details about what caused the system failure or when operations will return to normal. A more comprehensive update is expected as technical teams complete their investigation.
This incident marks another in a series of IT-related disruptions that have plagued the airline industry in recent years, highlighting ongoing challenges in modernizing critical infrastructure while maintaining uninterrupted service.