I just ran across an article saying all planes currently on the ground in the US are to remain on the ground until further notice. The FAA is saying it’s a communications issue. I assume if it was something bigger than that (like a terrorist attack) there would be a lot more news about it.
The stop was placed “DUE TO EXTRAORDINARY CIRCUMSTANCES AND FOR REASONS OF SAFETY.” The stop requires that all air traffic set to depart U.S. airports remain grounded.
https://www.axios.com/2026/11/13/faa-nationwide-ground-stop
The cause of the ground stop was not immediately clear, but an FAA spokesperson says there is a communications problem impacting Air Route Traffic Control Centers, which handle flights going across the country.
Looking at some of the bigger airports on FlightRadar24, you can see a ton of planes on the taxiways, though I don’t look at those airports very often, so maybe it’s how they always look.