It was ordered “due to extraordinary circumstances and for reasons of safety,” specifically a communications problem affecting Air Route Traffic Control Centers (ARTCCs). Transportation Secretary Sean Duffy confirmed it stemmed from a communication issue impacting all such centers, with FAA technicians investigating. Flights already in the air were generally allowed to continue, while inbound international flights were handled case-by-case. Departures were ordered to remain on the ground until further notice.
The FAA’s own National Airspace System status listed a ground stop for ALL airports under “EQUIPMENT / OUTAGE.” Some reports noted controllers losing radios and related systems (with the issue reportedly starting in the Kansas City Center area and spreading), and parts of the system reaching “ATC Zero” (no ATC services available in affected areas). Preliminary indications pointed away from a cyberattack.
This is extremely rare—only the third nationwide ground stop on record, after the one following the September 11, 2001 attacks and a January 2023 outage of the pilot NOTAM notification system. As of the latest available reports (around 4:55 PM ET), it remained in effect with no announced end time, though some unofficial pilot reports mentioned a possible window extending into the evening. Check your airline or the FAA’s fly.faa.gov status page for real-time updates, as this is a developing situation.