US air regulators on Friday issued a nationwide ground stop for departing flights, citing a communications problem affecting air traffic control towers.
The Federal Aviation Administration "issued a nationwide ground stop for all US airports following a communication issue impacting all Air Route Traffic Control Centers," the agency said. "FAA technicians are investigating the issue."
FlightRadar24, in a post on X, clarified that a ground stop means "NO flights may depart for US airports. Flights already in the air will be allowed to land."
The chief of Homeland Security, Markwayne Mullin, said there is no indication the aviation ground stop was triggered by a threat to the US.
"There was no indication, as of yet, that this was a nefarious attack against us, it's just a telecommunication outage, as of right now," Mullin said, adding officials were "not ruling out anything at this point."
Workweek business writer Trung Phan shared his guess as to what caused the ground stop, posting on X, "Gonna guess there high probability that the FAA grounding all flights in the US is related to an $875m AI tool it built called SMART that will 'assist in managing air traffic across the entire national air system' that the administration started rolling out" yesterday.
The FAA has announced similar orders in recent years on individual airlines due to communications issues, usually lasting a couple of hours or less. Systemwide groundings nationwide are far less common.
In January 2023, the FAA called a nationwide ground stop due to problems with the Notice to Air Missions system (NOTAM), which provides information to pilots about hazards, changes to airport facilities, and information that can affect flights.
That outage lasted just under two hours and was thought at the time to be the first nationwide grounding since 9/11.
Friday's FAA order came a day after US Transportation Secretary Sean Duffy formally asked Congress for $30.1 billion in funds to upgrade and modernize the US Air Traffic Control System.
The ground stop comes hours after a tanker collided with a docked riverboat in New Orleans, Louisiana.