United Air delays mount as tech issue grounds flights across US

Danny Lee, Bloomberg News on Aug 6, 2025

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Hundreds of United Airlines Holdings Inc. flights were delayed Wednesday evening, throwing travel plans into chaos, after a tech issue forced the carrier to ground flights across the U.S.

“Due to a technology issue, we are holding United mainline flights at their departure airports,” the world’s biggest airline measured by capacity said in a statement. “We expect additional flight delays this evening as we work through this issue.”

Airline tracking site Flightaware showed more than 820 United flights were delayed as of 9 p.m. New York time, accounting for 27% of scheduled services.

Flightradar24 showed planes backing up on taxiways, either waiting to depart or get an available gate to disembark arriving passengers, with similar scenes playing out at the airline’s hubs in Houston, Newark and Chicago.

In Washington, a United pilot told passengers on a Chicago-bound plane stuck on the tarmac that the issue was affecting all flights, before heading back to the gate. Other social media posts said the airline’s pilots were having difficulties with the system calculating the weight and balance of planes.

Ground stops were in place at airports including Denver, Houston, New Jersey’s Newark, San Francisco and Chicago, according to the U.S. Federal Aviation Administration on Wednesday evening — locations that are major hubs for United.

The issue comes just two weeks after Alaska Air Group Inc. temporarily grounded its entire fleet due to a data center equipment failure that affected several of the carrier’s key operating systems.

(With assistance from Catherine Larkin.)