US-wide ground stop triggered by air traffic control communication failure; cyber attack ruled out

Air traffic across the United States ground to a halt starting around 4 p.m. Eastern time Friday, with local media reporting the disruption appeared to stem from a communication failure at air traffic control centers rather than a cyber attack.

The Federal Aviation Administration announced Friday that it had halted all aircraft departures nationwide, citing "unusual circumstances and safety reasons."

It was the first nationwide ground stop the FAA had imposed since Jan. 11, 2023.

The FAA said all departing flights must remain grounded until further notice, adding that international flights bound for the United States would be managed on a case-by-case basis.

The disruption is believed to have stemmed from a failure in air traffic control communications.

Transportation Secretary Sean Duffy posted on social media citing "a communications issue affecting all Air Route Traffic Control Centers" and said FAA technicians were investigating the problem.

Law enforcement officials told CNN that early findings suggested the incident was not the result of a cyber attack. A source told CBS the situation was related to radio frequencies and how pilots communicate with controllers.

Meanwhile, as of 4:45 p.m., more than 7,800 flights within the United States had been delayed and about 350 canceled. The New York Times reported that passengers were deplaning and leaving major hub airports including those in Chicago and Denver.