Air travel across the United States remained heavily disrupted after air traffic was shut down for more than four hours on Friday, following a maintenance upgrade that crippled communications. The New York Times reported that operations were returning to normal, but delays and cancellations continued to ripple through the system.

Forbes reported that the disruption had not yet fully cleared by Sunday, when more than 4,000 flights in the U.S. were delayed and another 1,600 were canceled as of early afternoon. Taken together, the figures point to nearly 6,000 disruptions, underscoring how far the effects of the ground stop extended beyond the hours it was in force.S2