A nationwide ground stop across United States airspace ended around 8:15 p.m. ET, after more than four hours that disrupted air travel across the country and reached into Canadian travel plans. Some domestic departures have resumed, and officials expect operations to return to normal gradually, with full service in time for the Thanksgiving holiday. Passengers have been advised to check directly with their airlines before heading to airports.
According to FlightAware, more than 2,500 US flights were cancelled on Saturday, and hundreds more were delayed. Airlines and aviation officials warned that the ripple effects of the stoppage will be felt for several days as aircraft and crews are repositioned. Transportation Secretary Sean Duffy said the recovery will not be quick and warned that further disruptions are possible as the system works through the backlog.
The stoppage was linked to new technology introduced into the air traffic control system that overloaded aging equipment. The overload caused intermittent communication and radar gaps, which prompted the halt as a precaution. Homeland Security Secretary Markwayne Mullin said no lives or flights were at risk. Microsoft said an outage on Thursday was not connected to the stoppage, and Mullin said there is no indication of a cyberattack.
The stoppage lasted more than four hours, the longest such halt in 25 years. Modernization of the air traffic control system began last year with $12.5 billion from Congress. The administration is now seeking an additional $30 billion to finish the work, a request that places the aging infrastructure at the centre of the debate over how quickly the system can be upgraded. Officials have not said when the full modernization will be complete.
Flights from the San Francisco region were cleared for transpacific departures, including routes to Hawaii and Asia, while international services have been handled on a case-by-case basis. Europe's aviation safety agency paused departures bound for the United States from 5 p.m. ET on Friday until midnight, a measure that added to the disruption for travellers on transatlantic routes. Each step of the pause compounded delays for passengers who had already been rebooked once or twice.
Under passenger rights rules, airlines must offer free rebooking or refunds for cancelled flights. Travellers from Canada who are booked on US-bound or connecting flights are advised to confirm their status with their carrier, since schedules may continue to shift in the coming days while the system returns to normal operation. Anyone whose trip was cancelled can seek a refund rather than accept an alternative itinerary that no longer suits their plans.