United Airlines has officially lifted a nationwide ground stop that disrupted air travel across several major U.S. cities on Wednesday evening. The temporary halt in operations stemmed from a technology glitch involving the airline’s internal system, causing hundreds of flight delays and several cancellations. The issue, which began around 6:00 p.m. ET, forced United to halt all domestic departures from key hubs, including Newark, Denver, Chicago O’Hare, Houston, San Francisco, LaGuardia, and Washington Dulles. Flights that were already in the air continued to their destinations without any disruptions.
Unimatic System Failure Behind Glitch
United’s Unimatic system caused the disruption. This internal software platform manages flight operations, load balancing, crew schedules, and real time tracking. The malfunction in the system prevented flight dispatchers from uploading necessary data, forcing the airline to pause operations as a precautionary measure. By approximately 10:00 p.m. ET, United announced that the issue had been resolved and the ground stop was lifted. However, the ripple effect of delays extended well into the night. Flight tracking services reported that United delayed over 1,000 flights nearly 35% of its daily operations. Some airports, like Newark and LaGuardia, experienced more severe congestion, with dozens of flights either postponed or canceled altogether.
FAA and DOT Confirm No Cyber Threat
The Federal Aviation Administration (FAA) confirmed that United’s internal systems caused the issue and that it didn’t affect the broader U.S. air traffic network. FAA officials worked closely with the airline to coordinate the resumption of flights and reduce congestion where possible. The Department of Transportation also confirmed there was no evidence of a cyberattack or security breach.
United Offers Compensation to Affected Travelers
U.S. Transportation Secretary Sean Duffy received a briefing on the incident and emphasized the importance of technological resilience in aviation. United has classified the delay as a “controllable irregularity,” meaning it was within the company’s ability to manage. As a result, the airline committed to providing accommodations and compensation for affected passengers, including hotel stays and meal vouchers where necessary. United Airlines has since resumed full service, though officials continue to monitor for any residual effects. Travelers are encouraged to check their flight status before heading to the airport and to follow updates on United’s official platforms.
