The US Federal Aviation Administration (FAA) on Friday night lifted the nationwide ground stop it had ordered in the afternoon, after some four and a half hours of airspace closure that left thousands of flights cancelled. Donald Trump’s administration blamed the failure on overloaded, outdated analogue telecommunications equipment at air traffic control centres, ruled out a cyberattack for now and warned that the return to normal would be slow.
Airspace reopened at 8.15 p.m. Eastern time (10.15 p.m. in Montevideo), according to Transportation Secretary Sean Duffy. According to his account at a White House press conference, at 3.36 p.m. radar and communications at control centres began giving inconsistent data, and shortly before 4 p.m. the FAA ordered that no aircraft take off. Duffy said the switches and routers of the old analogue telecommunications system became overloaded with data and began giving erroneous information. At that moment more than 3,500 aircraft were in the air, and they landed normally.
Homeland Security Secretary Markwayne Mullin said the failure was unrelated to Thursday’s global Microsoft outage and that, “as far as we have seen”, there was no cyberattack, although the investigation remains open.
More than 6,000 flights were cancelled and more than 25,000 delayed, according to FlightAware. Duffy spoke of “tens of thousands” of people stranded at airports, and the federal emergency agency, FEMA, activated its centres to ensure no passenger went without medication. Recovery will depend on the availability of pilots and crews, and flights that did not leave on Friday will be rescheduled from Saturday, less than two weeks before Thanksgiving.
Duffy used the briefing to ask Congress, which Democrats will control from January, for US$50 billion in emergency funding to build a new air traffic control system, on top of the US$12.5 billion already approved. According to the secretary, previous administrations received US$15 billion over 25 years and “barely anything was done”.
It was the third nationwide ground stop in US history, after the September 11, 2001 attacks and January 2023, when the pilot notification system failed.