Major airlines have cancelled more than 4,000 US flights and delayed 3,000 more as the United States sought to recover from the longest nationwide ground stop in 25 years, which left passengers scrambling for seats and disrupted travel around the world.
The US air travel schedule should be back to normal by the end of tomorrow, administrator of the Federal Aviation Administration (FAA), said.
Bryan Bedford said airlines “will still have delays and cancellations” but promised that the “worst is behind us”.
New technology being added to the nation’s air traffic control system overloaded antiquated equipment and caused “intermittent” communications and radar gaps, leading to the ground stop that lasted more than four hours yesterday, Trump administration officials said.
Secretary of Transportation Sean Duffy said a FAA contractor, L3Harris LHX.N, had been working on replacing a section of the system’s old copper wire with new fibre wire, and that work somehow caused the system overload.
Mr Duffy said officials were investigating whether contractor “incompetence” or a faulty router was the cause.
“Our contractor didn’t meet the moment,” Mr Duffy said.
The ground stop forced airlines to cancel nearly 10,000 flights and delay more than 7,000 others in one of the worst travel days in US history.
Delta Air Lines, United Airlines and American Airlines AAL.O all cancelled about 20% of their flights today, while JetBlue cancelled 40%.
Mr Duffy said an AI scheduling tool or cyberattacks were not to blame.
Though the FAA eventually lifted the ground stop at around 1.15am Irish time, the disruption for passengers was far from over, with tens of thousands of people still stranded at airports around the US.
Airlines were trying to unclog airports and get flight crews and other personnel in position to recover from the massive disruption.
Many major airports said they could not handle any more diversions as they tried to get airplanes back in the sky. Many college football teams were stranded yesterday and struggled to find ways to get to games today.
American Airlines late yesterday said it was prioritising flights to international destinations and to smaller cities outside its major hubs to position aircraft and crews for a faster recovery.
The FAA issued the ground stop because of an outage that appeared to be affecting a network that handles critical radio frequencies used by air traffic controllers to communicate with pilots, according to two airline officials.
The contractor that oversees the network, L3Harris, did not respond to a request for comment.
Watch: Passenger captures cabin announcement about US nationwide flight grounding
Funds sought to fix ’emergency’
The problem is the latest and most dramatic sign of strain on a US air traffic control system beset by aging technology, equipment and communications problems and a shortage of several thousand controllers.
Transportation Secretary Sean Duffy yesterday called for $50 billion in funding to upgrade air traffic control systems, up from $30bn he had sought earlier.
“This is an emergency,” he said.
Mr Duffy said the trouble began at 3.36pm eastern time, when air traffic control centres experienced instability in 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,” Mr Duffy said, adding that air traffic personnel never completely lost radar or communications as they guided thousands of planes to landings.
Mr Duffy said the immediate problem had been fixed and that flying was safe, but warned that a broader overhaul of the air traffic control system was needed to prevent similar failures.
Earlier yesterday, before the outage, the White House and Department of Transportation had urged Congress to approve $30.1bn to upgrade aged airports and air traffic control infrastructure.
“What we have is an incredibly old air traffic control system,” Mr Duffy said. “Give us the money to fix it.”
Homeland Security Secretary Markwayne Mullin said there was “zero evidence” so far that the outage resulted from a cyberattack or a rogue AI system, though investigators had not ruled out either possibility.
The National Security Agency was working with the Department of Homeland Security on the investigation, he added.
Pain for passengers
From Boston to Seattle and New York to Los Angeles, passengers last night crowded departure halls and airline desks as delays and cancellations mounted and aircraft remained parked at gates.
“I might cry at some point but not yet,” said one passenger who was stuck at Newark Liberty International Airport after the aviation meltdown disrupted her British Airways flight to London.
Because the FAA was responsible for the delays, airlines are not required to provide compensation to stranded passengers.
Dublin Airport has warned that flights between Ireland and the US could be affected this morning with delays and a small number of cancellations.
The only other US nationwide ground stop since the 11 September attacks came in January 2023, when the FAA halted domestic departures for about 90 minutes.
Investors were already pricing in a financial hit to airlines. Shares of American AAL.O, United UAL.O and Delta DAL.N fell between 1% and 2% in after-hours trading late Friday, while JetBlue Airways JBLU.O dropped about 3%.
Shares of L3Harris traded down about 3% after hours.
Additional reporting PA
