US air regulators on Friday issued a rare nationwide ground stop for all departing flights, citing a communications problem affecting air traffic control towers, a move that caused immediate confusion for travelers. The Federal Aviation Administration said it had "issued a nationwide ground stop for all US airports following a communication issue impacting all Air Route Traffic Control Centers," adding that "FAA technicians are investigating the issue." At Las Vegas airport, a Southwest Airlines check-in desk told passengers there would be no flights taking off for 24 hours.

The FAA has issued similar orders in recent years for individual airlines because of communications issues, usually lasting a couple of hours or less. Systemwide groundings across the country are far less common. In January 2023, the FAA called a nationwide ground stop because of problems with the Notice to Air Missions system, which provides pilots with information on hazards, changes to airport facilities and other matters that can affect flights. That outage lasted just under two hours and was thought at the time to be the first nationwide grounding since 9/11.S2S3

The grounding came a day after US Transportation Secretary Sean Duffy formally asked Congress for $30.1 billion to upgrade and modernise the US Air Traffic Control System. In a letter to lawmakers, Duffy and Office of Management and Budget Director Russell Vought wrote that the investment "is critical to complete the modernization of our national airspace," including a resilient telecommunications backbone for air traffic controllers, modern hardware and software, state-of-the-art control towers, and world-class airport infrastructure.S2S3