United Airlines said the tech issue that led to the grounding of its flights for a few hours on Aug. 6 at major U.S. airports, including Chicago, Denver, and Houston, has been resolved.
In an update at 10 p.m. ET, United told USA TODAY that the “underlying technology issue” was resolved and that they were working to restore normal operations. The Chicago-based airline added that it was anticipating residual delays and working to get customers to their destinations.
“Due to a technology issue, we are holding United mainline flights at their departure airports,” United Airlines said in an earlier statement. “Safety is our top priority.”
Transportation Secretary Sean Duffy said he was briefed on United Airlines’ “internal tech outage” and noted that the FAA was in contact with the company’s systems operations team.
“The issue was specific to United’s operations and is unrelated to the broader air traffic control system,” Duffy said in a statement on X.
The system outage prompted ground stops for United Airlines flights at multiple airports across the United States, according to the Federal Aviation Administration. The agency said it was aware of the technology issue disrupting the airline’s operations.
By 10:25 p.m. ET, FlightAware, which monitors air travel, showed that 1,038, or 34%, of United flights, had been delayed on Aug. 6.
“Some delays may continue as they work through the recovery process,” the FAA told USA TODAY. “We’ve offered full support to help address their flight backlog and remain in close contact with United.”
The outage comes weeks after Alaska Airlines grounded all its flights for about three hours due to an IT outage, the second time in just over a year. In April 2024, Alaska grounded its entire fleet due to an issue with the system that calculates the weight and balance of its planes.
United Airlines said the issue was related to its Unimatic system, which “houses information about each flight that is then fed to other systems, including those that calculate weight and balance and track flight times.”
The outage began at around 6:12 p.m. ET and was resolved within a few hours, according to the airline. The company added that it was treating the problem as a controllable delay and paid customer expenses, such as hotels, when applicable.
The airline noted that the outage was not associated with “recent concerns about cybersecurity in the airline industry.”
A system outage was causing flight disruptions at Newark Liberty International Airport and other airports, with some travelers delayed for hours, the Newark Airport said in a post on X. The airport urged travelers to check with their airline on the status of their flights.
United Airlines, in its responses on social media to frustrated customers, wrote: “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.”
Travelers expressed their anger with the airline, with one posting: “Another ground system failure at @EWRairport has me locked on the tarmac for nearing 2 hours now…perhaps look for another hub @united.”
Around 9:30 p.m. ET, FlightAware.com was reporting departure delays of an average of 45 minutes and all inbound flights were being held at their point of origin until 10 p.m.
Contributing: Reuters

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