Arabic version: إدارة الطيران الفدرالية ترفع وقفاً وطنياً للرحلات دام أربع ساعات

According to BBC News, the US Federal Aviation Administration lifted a nationwide flight ground stop that lasted more than four hours, the longest such stoppage since the 11 September 2001 terrorist attacks. The FAA said the measure was taken because of “extraordinary circumstances” involving a communication issue affecting all air traffic control centres.

The FAA announced at 15:54 EST that all flights departing within the United States would be grounded until further notice. More than 3,500 aircraft were already in the air; some were diverted while others continued to their destinations. The agency reopened the skies at 20:15 EST, and some flights had earlier been permitted to depart from San Francisco International Airport.

FlightAware recorded more than 8,500 delayed flights and nearly 8,000 cancellations on Friday. International disruption also followed: Eurocontrol suspended US-bound traffic from its member states at the FAA’s request, Sydney airport halted US-bound flights, and Air Canada cancelled services between Canada and the US.

Transportation Secretary Sean Duffy said an overloaded legacy communications system had affected communications and radar. He described the system as analogue telecom whose switches and routers were overwhelmed with data, and said a complete overhaul could cost an estimated $50bn. Homeland Security Secretary Markwayne Mullin said there was “zero evidence” of a cyber-attack, no link to a global Microsoft outage, and no indication that the public had been in danger.

Duffy said the disruption could create a ripple effect for several days, leaving tens of thousands of travellers stranded. Delta and United said they were resuming operations, American said it was seeking to operate as many remaining flights as possible, and JetBlue said it would resume flights on Saturday morning.