US Airspace Reopens After Nationwide Flight Grounding, Delays Expected

Flights resumed across the US on Friday night after a communications outage at air traffic control centres forced the Federal Aviation Administration (FAA) to impose a nationwide ground stop, disrupting thousands of flights and leaving passengers stranded at airports.

US Transportation Secretary Sean Duffy confirmed that the FAA lifted the ground stop at 8.15 pm Eastern Time (ET). However, the resumption of departures did not immediately restore normal flight schedules, as airlines faced a backlog of delayed flights and aircraft and crew members out of position. Officials warned that disruptions could continue over the weekend and into the coming days.

The FAA imposed the ground stop after communications problems affected 22 air route traffic control centres responsible for directing aircraft travelling between airports. The restriction applied to departing flights, while aircraft already airborne continued to be managed by air traffic controllers, with some flights diverted to other airports. Some international departures were also handled separately on a case-by-case basis, the AP reported.

FAA lifts nationwide ground stop after communications failure

At least 827 flights had been diverted by 7.05 pm ET, according to figures from aviation analytics company Cirium cited by the Associated Press. Of these, 670 were sent back to their original departure airports, while 157 were redirected elsewhere.

Duffy said air traffic control centres and systems were operational again but cautioned that clearing the backlog would take time. He also warned that flight schedules could remain affected over the weekend as airlines worked to resume normal services.

About 11,000 flights carrying more than 1.5 million passengers were scheduled to depart US airports after 4 pm ET, according to the AP.

Ageing air traffic control system under scrutiny

The outage has renewed questions about the condition of the US aviation network, which relies on ageing air traffic control infrastructure. Duffy said the system's switches and routers had become overloaded with data, resulting in inconsistencies in the information being transmitted to air traffic control centres.

"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," Duffy said, according to Reuters.

Homeland Security Secretary Markwayne Mullin said the introduction of new technology into the older air traffic control system had overwhelmed existing equipment. He described the failure as apparently mechanical and said there was no indication of a cyberattack, the AP reported. Officials were continuing to investigate the cause of the communications disruption.

The communications problems did not appear to be linked to the FAA's new AI-powered forecasting system, which is being introduced to help predict problems in the skies. Mullin said there was no indication of a connection, while Air Space Intelligence (ASI), the company behind the system, said the ground stop was not caused by its technology, according to the AP.

The previous nationwide FAA ground stop was in January 2023, after a malfunction in its system for sending safety notices to pilots. Before that, a nationwide ground stop was imposed following the September 11, 2001 attacks, the AP reported.

Airlines warn of further flight disruptions

Although the FAA lifted the ground stop on Friday night, airlines faced the task of repositioning aircraft and crew members displaced by the disruption, making an immediate return to normal schedules difficult.

JetBlue cancelled its remaining domestic flights on Friday evening, with exceptions for Europe-bound departures from Boston Logan International Airport and New York's John F. Kennedy International Airport.

The airline warned that disruptions could continue into Saturday, including further cancellations, according to the AP.

Duffy warned that restoring normal operations would take time, with delays expected to continue over the coming days.