The United States Federal Aviation Administration lifted a nationwide flight ground stop on Friday following a communications failure at air traffic control centres that disrupted operations at US airports, triggering the longest shutdown since the September 11, 2001, attacks.
Transportation Secretary Sean Duffy said US airspace reopened at 8:15 p.m. Eastern Time (0115 GMT), but warned that flight departures would resume gradually as airlines worked to restore normal operations.
“It’s going to be slow,” Duffy told reporters at the White House.
According to FlightRadar24, more than 6,600 flights were cancelled and 8,600 delayed, while another 1,500 cancellations had already been recorded for Sunday.
Aviation analysts warned that the four-hour nationwide grounding could disrupt airline schedules for several days.
Duffy said tens of thousands of passengers were stranded at airports across the country.
He added that he and Homeland Security Secretary Markwayne Mullin had met with President Donald Trump in the Oval Office to discuss the disruption.
The outage is the latest and most significant indication of mounting pressure on the US air traffic control system, which has been plagued by ageing technology, equipment and communication failures, as well as a shortage of thousands of controllers.
Duffy said the disruption began at 3:36 p.m. after air traffic control centres experienced instability in their radar and communications systems.
“Our switches, our routers actually got overloaded with data and they started to give us inconsistencies in the data from those routers and because of that we shut the system down,” Duffy said.
