The Federal Aviation Administration lifted a nationwide ground stop that had halted all departing US flights for hours, leaving thousands of flights delayed or canceled. Reports put the disruption at more than 15,000 flights affecting about 1.5 million passengers.

The FAA attributed the stop to a telecommunications outage, and Transportation Secretary Duffy has since detailed the timeline of the ground stop and called for more FAA funding. Officials have said the stop was not a cyberattack, with DHS stating the nation's systems are built to handle crises like this.S2

According to the reports, the failure was linked to an outdated air traffic control system. Officials also examined whether a new AI air traffic system was involved, and an AI startup said its software did not cause the stop. The reports said an upgrade overloaded legacy equipment, prompting a precautionary shutdown, and that the episode has intensified calls for about 50 billion dollars to modernise ageing aviation infrastructure.S1S2

Passengers were stranded at airports including Raleigh-Durham and Chicago, where travellers sought answers about checked bags, and some airports began running out of space for planes during the stop.S2