The US Federal Aviation Administration on Friday afternoon issued a nationwide ground stop on flights due to a frequency outage with ATC controllers. All departures have been halted until further notice, the FAA said in an alert. Over 7,000 flights have been affected.
“FAA issued a nationwide ground stop for all U.S. airports following a communication issue impacting all Air Route Traffic Control Centers,” US Transportation Secretary Sean Duffy said in a X post. “FAA technicians are investigating the issue. We will provide immediate updates as we have them.”
Journalist Anna Giaritelli shared a FAA release which cited “rolling frequency outage” as the cause of the ground stop. A frequency outage occurs when the radio communication infrastructure that enables pilots to communicate with Air Traffic Control (ATC) controllers fails to function properly. A country-wide failure, at such a large scale, is unprecedented.
However, the flights already in the air will be allowed to land.
The directive, issued by the FAA Command Center, took effect at 3:54pm ET on November 13, Friday, and is scheduled to remain in force until 11:30pm ET.
Inbound international flights will be handled on a case-by-case basis, according to the advisory issued by the Air Traffic Control System Command Center (ATCSCC).
The notice did not specify the circumstances behind the order, except calling it “extraordinary,” or provide details about when normal flight operations would resume. Reuters reports that at least 7,000 flights have been delayed or canceled due to the ATC controller issues.
The last time the FAA issues a nationwide ground stop was in 2023. It lasted a little less than two hours.
Also read: US flights grounded nationwide: A look back at the last major FAA shutdown in 2023
ATC’s new AI tools under the scanner
The major nationwide ground stop has brought under scrutiny a newly deployed AI tool to assist ATC in controlling air traffic. The SMART tool was deployed across the ATC’s system to assist in managing air traffic across the entire national airspace system,” the FAA had said. The tool was deployed on Thursday, November 12.
Called the Strategic Management of Airspace Routing Trajectories (SMART), it was deployed as a pilot project first at the Washington, D.C., airspace in September. A report by Ars Technica claimed the system was able to save up to f $345 per flight with jet fuel at $4:31 per gallon.
The ATC handles over 100,000 flights daily, according to FAA data.
This story is developing.