Flights resumed in the US, but the crisis is not over: Thousands of flights canceled

US flights resumed after a communications failure halted air traffic for several hours, but more than 4,000 flights remained canceled and full normalization of air traffic is not expected until Sunday. The disruption stemmed from an outage affecting communications systems used in flight operations, forcing authorities to ground departures across the country before clearing operations to restart. The mass cancellations underscore how dependent the US aviation system is on a single communications link and how quickly a technical failure can cascade into nationwide travel disruption. Watch for updated cancellation and delay figures from airlines and for any statement from regulators and carriers on the cause of the outage and on contingency measures.