United Airlines has resolved a technology issue that forced the grounding of hundreds of flights across the United States on Wednesday, causing widespread delays. The airline confirmed the problem was linked to its Unimatic system, which provides critical flight information to other operational systems, including those for weight and balance calculations and flight time tracking.
Ground stops were issued at several major United hubs, including Newark, Denver, Houston, Chicago, and San Francisco, according to the Federal Aviation Administration (FAA). The US transportation secretary, Sean Duffy, clarified on social media that the issue was specific to United's operations and not related to the broader air traffic control system.
United stated it was treating the disruption as a controllable delay, meaning it would cover customer expenses such as hotel accommodation where applicable. As of Wednesday evening, tracking site FlightAware reported that 1,038 United flights—34% of the airline's total—had been delayed.
The incident follows a similar IT outage at Alaska Airlines just weeks earlier, which grounded its entire fleet for about three hours. In April 2024, Alaska also faced a grounding due to a problem with its weight and balance calculation system.
