The US aviation system has returned to full operations after a nationwide ground stop disrupted thousands of flights, with officials saying the disruption was triggered by technical problems during maintenance work and not by foreign actors.Transportation secretary Sean Duffy said the work was being carried out by telecommunications contractor L3Harris as part of a long-running effort to modernise the country’s air traffic control network. A router being worked on began flooding other air traffic control systems, creating communication problems with aircraft and prompting the Federal Aviation Administration (FAA) to halt flights as a precaution.Duffy said investigators were examining whether the incident resulted from a faulty piece of equipment or incompetence on the contractor’s part. L3Harris had not commented on the outage as of the press conference.The disruption had initially raised concerns about a possible cyberattack or foreign interference. Duffy said FBI director Kash Patel, director of national intelligence Jay Clayton and other officials joined a conference call on Friday because of concerns about whether the incident involved a cyberattack or a threat from another country. The White House Situation Room was also involved, with national security agencies brought in to examine the incident.However, officials are now confident that the disruption had a technical cause. FAA administrator Bryan Bedford said investigators had found “zero evidence of anything nefarious” and no evidence that artificial intelligence was involved.
Thousands of flights affected
The FAA ordered a four-hour ground stop while authorities investigated the problem and worked to stabilise the system. Bedford said the stoppage was intended to reduce pressure on the network while officials assessed the safety of operations.Of the roughly 20,000 flights affected, the FAA managed to recover about 8,000 during the ground stop. Around 12,000 could not be recovered, including approximately 9,000 commercial flights and 3,000 private and general aviation flights.Although the system was stable on Saturday morning, Bedford estimated that between 4,000 and 5,000 of the 41,000 flights scheduled for the day could still be cancelled. He said the worst of the disruption was over.Passengers affected by cancellations should contact their airlines directly, Bedford said. Carriers should either re-accommodate them on another flight or provide a full refund.
Officials warn ageing infrastructure remains a risk
Duffy said the incident had exposed the vulnerabilities of an ageing telecommunications network used by the country’s air traffic control system. The replacement of copper wiring with fibre has been under way for years, but he said the existing infrastructure would remain in use until a new system is built.He defended carrying out the upgrade during the day, saying the work took place at a remote location and should not have caused such widespread disruption. At larger facilities, similar switchovers are generally carried out at night because they can have a greater impact on operations.Bedford said the system was operating as safely as it had two weeks earlier, but warned that failures would continue unless the infrastructure was replaced. Duffy renewed his appeal for Congress to approve $50 billion to build a new air traffic control system, asking how long the country could afford to wait for modernisation.The transportation secretary said the government would remain dependent on L3Harris, which operates the existing telecommunications network, until new infrastructure is in place.Bedford said the FAA would hold a transparent hearing into what caused the disruption and use the findings to determine what changes were needed.