US ground stop after communications failure lifted; thousands of flights cancelled

The ground stop

On Friday, 13 November, the Federal Aviation Administration ordered a halt to departures at all US airports at 15:36 Eastern time, which is 22:36 in Greece, after communications problems hit air traffic control centres nationwide. The agency said at 15:54 Eastern time that all departures remained grounded until further notice, by which point more than 3,500 aircraft were already in the air. The ban was lifted at 20:15 Eastern time, or 03:15 Greek time on Saturday, 14 November. Greek outlets put the length of the halt at between about four and five hours, and describe it as the longest nationwide halt to flights since the 11 September 2001 attacks. Aircraft already airborne landed under standard procedures, and some were diverted to alternative airports.

Officials give their account

Transportation Secretary Sean Duffy told a press conference at the White House that the problem stemmed from an analog telecommunications system whose switches and routers were overloaded with data and knocked offline. He said communications had not failed completely but had suffered intermittent disruptions, and warned that the system would keep failing until it was fully upgraded. Homeland Security Secretary Markwayne Mullin attributed the overload to the introduction of new technology into an old air traffic control system. Mullin said officials had seen no evidence of a cyberattack and ruled out any link with the Microsoft service outage that began on 12 November. US media reports, relayed in Greek coverage, linked the disruption to SMART, an AI-based tool costing about 875 million dollars that the FAA extended on 10 November to 22 regional centres. The FAA said the tool plays a supporting role, and when asked whether the rollout could be linked, Mullin said the department was examining it.

Flights and passengers

FlightRadar24 counted more than 6,600 cancelled flights and 8,600 delayed flights, and said a further 1,500 flights scheduled for 15 November had already been cancelled. FlightAware counted nearly 8,000 cancellations and more than 8,500 delays on Friday alone. Duffy said tens of thousands of passengers were stranded at airports across the country and warned that airlines would need time to restore normal operations. American Airlines, Southwest Airlines and United Airlines said their aircraft began flying again after consultations with the FAA. Eurocontrol said flights from its 42 member countries to the United States were suspended until further notice at the FAA's request, and flights to the US were also suspended at European airports and in Australia.

Funding and history

Congress approved 12.5 billion dollars last year for the FAA's aging communications system. On Friday, the FAA and the White House asked Congress for another 30.1 billion dollars to address other issues. Duffy estimated the full upgrade at 50 billion dollars, saying he wanted 50 billion where the president had requested 30 billion. The previous nationwide departure ban came in January 2023, when a pilot alert system was taken offline, and before that after the 11 September 2001 attacks.

Approved by Congress last year12.5

Requested by FAA and White House on 13 November30.1

Duffy's estimated upgrade cost50

Approved by Congress last year

12.5 USD billions

Requested by FAA and White House on 13 November

30.1 USD billions

Duffy's estimated upgrade cost

50 USD billions

Data from the article text

Trump's response

Donald Trump stayed unusually quiet for several hours while aircraft were grounded, according to Greek reporting. A senior White House official said he was receiving regular updates and had spoken by phone with Duffy. In a Fox News interview, Trump said the disruption was a telecommunications problem and not a cyberattack. The Wall Street Journal reported that the outage stemmed from interference on the radio frequencies controllers use to talk to pilots.