FAA grounds all US flights due to 'telecommunication outage' — officials say ' no indication...that this was a nefarious attack,' but they can't rule out a cyberattack yet

For one of the few times in 25 years, the FAA has called a ground stop for all air traffic in the US. US officials said a telecommunications issue has hampered Air Traffic Control Centers across the US and their ability to communicate with planes in the air.

"Due to extraordinary circumstances and for reasons of safety. Attention all aircraft operators. By order of the Federal Aviation Command Center, all airports are ground stopped."

While US Transportation Secretary Sean Duffy has yet to issue a public statement, Department of Homeland Security Markwayne Mullin told reporters that this grounding, or the cause of it, "is not a threat to the US," and added it was a telecommunications outage.

He did not detail the exact affected technology, though, when asked about the coincidence of the massive Microsoft Outlook outage yesterday and this today, Mullin said, "I don't see any reason to connect those two at all."

On the possibility that this is a cyberattack, Mullin said they were not ruling anything out and "As we investigate what caused this, we always have to assume — as many cyberattacks take place —we make that assumption, but that's not known."

The ongoing grounding comes a day after the FAA made an announcement of its AI-backed SMART system (Strategic Management of Airspace Routing Trajectories) to more airports. However, that rollout started back in September. So any connection there would be conjecture.

There was a moment, though, when someone asked Mullin about that AI system, and Mullin quipped, "We call it 'SI' around here."

As of now, air traffic control systems around the country are managing landings on what Mullin called "a case-by-case basis."

We started tracking the skies over the US via Flightradar24 more than an hour ago, and its depiction of in-flight planes and the direction they're heading over the last hour or so is remarkable. It went from being a fairly normal flight day to a visually chaotic race back home. Flights that may have taken off appear to have been rerouted back to their nearest airports.

While JetBlue and American Airlines websites make no mention of the FAA grounding, Delta has a banner at the top of its site and recommends that everyone check their Delta App for their flight status.

For now, Mullin said pilots and air traffic controllers can communicate "at certain levels, but they have some " overwhelmed" communication systems.

Online pundits, including pilots and aviation experts, think there may be a fairly pedestrian issue. Scott Manley, a YouTube science expert and pilot, wrote on X:

"It sounds to me like the ATC outage is limiting the ability for enroute centers to communicate with each other. As aircraft move across the country, they get handed off from one controller to the next, and your flight information is handed between controllers in a separate channel."

Whatever the cause, it may take a day or more to untangle this mess.