US airlines scrambled Saturday to restore disrupted schedules after a four-hour nationwide flight grounding triggered by an air traffic control network failure, with thousands of cancellations and delays expected to ripple through the weekend.
The Federal Aviation Administration (FAA) lifted the ground stop at 8:15 p.m. Friday (9:15 a.m. Saturday in Manila), ending an approximately four-hour shutdown triggered by a telecommunications and networking problem affecting air traffic control systems.
Transportation Secretary Sean Duffy cautioned that returning to normal operations would be slow, as airlines worked to reposition aircraft and flight crews displaced by the disruption.
FAA Administrator Bryan Bedford and Duffy said airlines expected flight schedules to regain normal operations by the close of business Sunday, although some residual delays could persist.
The November 13 disruption stemmed from problems during an upgrade of the air traffic control network from legacy copper wiring to fiber-optic technology, officials said.
A router involved in the transition began flooding other network routers with excessive connection requests, reportedly generating more than 1,000 attempts every four to five seconds.
The resulting data overload destabilized radar and communications streams connecting air traffic controllers with aircraft across multiple Air Route Traffic Control Centers.
Unable to immediately establish the full extent of the problem or rule out the risk of losing contact with aircraft, the FAA ordered the nationwide grounding as a safety precaution.
Officials said there was no evidence that the outage resulted from a cyberattack, foreign interference or an artificial intelligence malfunction.
The disruption exposed the vulnerability of critical aviation infrastructure to failures during technology upgrades, even as authorities work to modernize aging air traffic control systems.
While the immediate technical problem was addressed, thousands of passengers faced another day of uncertainty as airlines worked to restore aircraft rotations and crew assignments.
