US aviation crisis persists as over 6,200 flights cancelled, 7,500 delayed

Bedford had estimated that between 4,000 and 5,000 of the 41,000 scheduled flights for the day would be cancelled. Globally, 6,843 flights were cancelled and 19,927 delayed, with a significant proportion of the disruptions involving US operations.

Among major airlines, Jet. Blue was the worst affected, with nearly 45 percent of its flights cancelled. American Airlines, United Airlines and Delta Air Lines also cancelled approximately a quarter of their scheduled flights.

Airlines have announced that affected passengers can reschedule their journeys for alternative dates without paying additional fees. Chicago's O'Hare International Airport was among the hardest-hit facilities, with more than 559 flights cancelled by 2pm. Another 68 cancellations were reported at Chicago Midway Airport.

At Atlanta's Hartsfield-Jackson International Airport, a major hub for Delta Air Lines, 479 flights had been cancelled by 12:30pm. In Texas, nearly 300 flights had been cancelled at Dallas-Fort Worth International Airport by 9am. Several passengers spent the night at the airport, with those scheduled to take connecting flights from Dallas facing particular difficulties.

At Houston's George Bush Intercontinental Airport, more than 310 flights had been cancelled by the evening, while disruptions also continued at William P. Hobby Airport. Transportation, airspace remains open and departures are operating safely.

However, passengers have been advised to prepare for further cancellations and delays as airlines face difficulties repositioning aircraft and crew and rebooking affected travellers. Authorities expect airlines to restore their full flight schedules by tonight.