United Airlines was forced to issue a nationwide ground stop for its entire fleet after a fire alarm sounded at its operations center in Chicago.
The ground stop was confirmed in a Federal Aviation Administration (FAA) advisory note on July 24, 2025, with the instruction coming into effect at 23:26.
United Airlines described the ground stop as “brief”, with no requirement for any flights to be diverted. Its regional subsidiary airline United Express was unaffected.
A spokesperson for United Airlines said: “A fire alarm sounded at our operations center, which caused employees to move to our nearby backup facility and resulted in a brief nationwide ground stop of United aircraft. Employees have returned to our primary operations center, and the ground stop has been lifted.”
All @united flights grounded in Newark because of a fire alarm issue in Chicago control center? Is this for entire US? pic.twitter.com/FZWv8lUllf
— Brian Land (@brianland) July 25, 2025
The United Airlines ground stop comes just days after Alaska Airlines experienced a brief nationwide IT outage that grounded all of its flights.
The outage, on July 20, 2025, caused a temporary, system-wide ground stop for both Alaska Airlines and Air Horizon flights.
Following the incident, Alaska Airlines said: “We sincerely apologize for the inconvenience and encourage guests to check your flight status before heading to the airport.”
Both incidents come at a time when the efficiency of the US commercial aviation industry is high on the priority agenda for the Trump administration.
1 comment
The ground stop was initiated at 1900 and release a just over an hour later. Not sure why FAA notice says 2326. The pilots and crew gave no reason for the stop. I’d like to know who pulled the alarm and if it was deliberate.