FAA issues nationwide US ground stop over communications issue

Flights in the U.S. were halted just one day after Microsoft's global outage.

The U.S. Federal Aviation Administration (FAA) issued a nationwide ground stop covering all airports on Friday at 3:45 p.m. ET. All departures from U.S. airports were put on hold until further notice.

An Air Traffic Control System Command Center (ATCSCC) advisory shared by Flightradar24 on Bluesky stated that the decision was made due to extraordinary circumstances and safety reasons. It noted that arriving international flights would be managed on a case-by-case basis, while some international flights were cleared for departure. Although the measure was initially scheduled to last until 11:00 p.m., the outage is expected to last longer.

U.S. Transportation Secretary Sean Duffy said in a statement on the social media platform X that the decision was made due to a communication issue affecting all Air Route Traffic Control Centers. Stating that FAA technicians were investigating the issue, Duffy reported that the agency was experiencing a temporary telecommunications outage and that all flights were being tracked.

Sources who spoke to CBS News as of 6:45 p.m. ET shared the first concrete detail regarding the cause of the malfunction. According to them, an update to the private communication network operated by L3Harris that connects the air traffic control system caused the system to reboot, then crash, leading to the communication outage.

Major airports were listed as closed, under ground stops, or delayed on the National Airspace System Status page. CNN correspondent Pete Muntean reported that due to the widespread radio frequency outage, pilots had to use the emergency frequency as a last resort.

Homeland Security Secretary did not rule out artificial intelligence (AI)

After recently ending the use of floppy disks in air traffic control, the FAA had begun rolling out a new artificial intelligence (AI) air traffic tool one day before the incident. Although there is no concrete evidence that this system played a role in the current outage, U.S. Homeland Security Secretary Markwayne Mullin did not completely dismiss the possibility in a televised statement.

Mullin said there were no indications of a cyberattack or terrorist threat. However, when asked whether the artificial intelligence (AI) system caused the problem, he stated that they could not rule anything out and were investigating the matter with all relevant agencies through the Cybersecurity and Infrastructure Security Agency (CISA). Meanwhile, ASI, the contractor that built the new artificial intelligence (AI) system, stated on X that the ground stop was not related to its SMART system or its FAA integration.

Describing the situation as a crisis, Mullin responded to a question on whether resolving the issue would take days or weeks by saying it was too early to tell. U.S. President Donald Trump had not made an official statement on the matter as of 6:45 p.m.

The FAA last halted nationwide domestic departures for less than two hours in January 2023 due to a crash in the pilot notification system. The last nationwide ground stop before that was issued on September 11, 2001.

The recent Microsoft outage is reportedly not connected to this incident. Microsoft also announced on social media that there is no link.