US flight chaos after order to ground planes; 1.5 million stranded

More than 1.5 million travellers were affected by a nationwide shutdown of US flight departures after a communications failure at air traffic control centres forced the Federal Aviation Administration (FAA) to ground flights across the country for more than four hours.

The disruption, one of the most extensive shutdowns of US air travel in decades, brought departures to a near standstill on Friday, leaving passengers stranded at airports, disrupting airline schedules and triggering thousands of cancellations and delays.

The shutdown also left aircraft and flight crews out of position, raising the prospect of knock-on disruptions extending into the weekend and potentially taking several days to clear.

The FAA eventually lifted the nationwide ground stop at 8.15pm Eastern Time (0115 GMT on Saturday), allowing domestic flights to resume. However, the reopening did not mean an immediate return to normal operations, with airlines having to gradually restore services and reorganise aircraft and crew schedules.

Transportation Secretary Sean Duffy warned that the recovery would be slow, although he expressed confidence that the system would be operating normally ahead of the Thanksgiving holiday travel period later this month.

The shutdown followed a communications failure affecting air traffic control centres across the country. The FAA issued the nationwide ground stop at about 3.44pm Eastern Time, citing safety concerns after experiencing instability in radar and communications systems.

The disruption affected air traffic control operations at regional centres and terminal radar approach control facilities (TRACONs), which manage aircraft movements around major airports. The FAA allowed aircraft already airborne to continue towards their destinations where possible, while new departures were halted. International arrivals were handled on a case-by-case basis.

More than 3,500 aircraft were in the air when the ground stop was issued, according to Duffy. More than 3,000 aircraft were subsequently brought down safely. However, the shutdown resulted in at least 827 flight diversions, with 670 aircraft returning to their departure airports and another 157 redirected to different airports, Cirium data showed.

The scale of the disruption was reflected in the flight schedules. Around 11,000 flights carrying more than 1.5 million passengers had been scheduled to depart US airports after 4pm Eastern Time on Friday.

Flight-tracking data showed more than 6,600 cancellations and 8,600 delays, while further cancellations were already being recorded for Sunday. The disruption affected major airports across the country, with passengers facing long waits, missed connections and uncertainty over rebookings.

Airline operations were also affected beyond the immediate shutdown. Aircraft and crews were left at airports other than those where they were scheduled to operate subsequent services, making it difficult to restore normal flight schedules even after departures resumed. Aviation analysts warned that the resulting disruption could take several days to clear.

The incident also affected cargo operations and sports teams travelling for weekend fixtures. FedEx said it was prepared to activate contingency arrangements to minimise disruption to its shipments. US airlines collectively transport around 61,000 tons of cargo daily to and from more than 220 countries, according to industry group Airlines for America.

Ageing technology under scrutiny

Duffy attributed the failure to ageing air traffic control infrastructure, including outdated telecommunications equipment and overloaded network routers.

He said instability in radar and communications systems was detected at around 3.36pm Eastern Time, with switches and routers struggling to process data and producing inconsistent information.

The problem prompted officials to shut down departures nationwide rather than risk operating an air traffic control system that could not reliably support communications between controllers and pilots.

Duffy described the infrastructure as an ageing system that still relies on older technology, including copper telephone lines and legacy equipment. He said the failure was not caused by the new AI-powered system being introduced by the FAA to predict air traffic problems.

Homeland Security Secretary Markwayne Mullin said there was no indication that the incident was the result of a cyberattack or a deliberate threat against the United States. He also ruled out a connection with the major Microsoft outage that had disrupted services earlier in the week, although he said investigations into the cause were continuing.

Mullin stressed that the shutdown was a precautionary measure and that passengers and aircraft had not been placed in danger.

Calls for major investment

The incident has renewed scrutiny of the condition of US air traffic control infrastructure, which has faced repeated technology failures, equipment problems and staffing shortages.

The federal government has been pursuing a major modernisation programme after Congress approved $12.5 billion in funding last year. The initiative includes replacing ageing copper telecommunications lines with fibre-optic infrastructure and upgrading radio systems used by air traffic controllers.

However, Duffy said substantially more funding would be required to complete the overhaul, with the administration seeking another $30 billion from Congress.

Calling the situation an emergency, he warned that further disruptions could occur unless the underlying infrastructure was upgraded.