The FAA issued a nationwide ground stop on November 13, saying only that "extraordinary circumstances" prompted it.
A ground stop is an order that keeps aircraft at their departure airports instead of letting them take off. A nationwide one applies that hold across the whole country rather than to a single airport or region. Beyond the agency's phrase, the material available gives no confirmed cause, no list of affected airports, and no duration, so none of those are stated here.
The wording signals that the FAA considers the situation unusual. It says nothing about what went wrong or who is responsible, and it gives travelers no sense of when departures will resume.
The closest recent precedent is January 11, 2023, when the FAA halted all domestic departures after its Notice to Air Missions system, which delivers safety alerts to pilots, failed. That stop was widely described as the first nationwide one since the September 11, 2001 attacks. It was lifted the same morning, but more than 1,300 flights were canceled and thousands more were delayed.
That episode shows how far a short national hold can ripple, because aircraft and crews end up out of position well after departures restart. What the FAA says caused this one, and how long it lasts, will decide whether it belongs in the same category.