It reports that Delta Air Lines and American Airlines have each cancelled more than 2,200 flights. United has cancelled 1,800 and Southwest nearly 1,400.
A nationwide ground stop affecting departing flights across the US has been lifted after almost five hours - but passengers can still expect lengthy delays as airports work through the backlog.
US Transport Secretary Sean Duffy and Homeland Security Secretary Markwayne Mullin held a news conference earlier, where they said the ground stop had been issued due to inconsistent data from outdated equipment.
Duffy blamed the outage on old air traffic control systems that have not been updated because of a lack of Congressional funding, and made a plea for $50bn in funding for a new "state-of-the-art system".
Mullin reassured the room that there was no evidence that the ground stop was caused by a cyber-attack, or linked to yesterday's Microsoft outage, and that "no one was ever at risk".
It is only the second time - and the longest - such a stop has been issued since right after the 11 September 2001 terrorist attacks.
Representatives on both sides of politics have called for an investigation into what happened on Friday evening to ensure "it never happens again"
The departures board at Heathrow Airport this morning shows a number of US-bound flights as "delayed" or "cancelled".
Cancelled flights include American Airlines services to Dallas, United Airlines services to Houston and a British Airways service to New York.
Specific reasons for the cancellations have not been given.
Passengers travelling from the US to the UK also continue to face disruption, with a number of cancellations showing on Heathrow Airport's arrivals board.
Responding this morning on X to a user who said they had been stuck on the tarmac for two hours, despite the ground stop being lifted, BA said: "Unfortunately, many flights have been disrupted, so it may take some time to get all flights on their way."
The airline is encouraging passengers to check their flight status, but tells passengers to "travel to the airport as planned and arrive for your original departure time".
In a statement issued overnight, Virgin Atlantic also urged customers to check their flight status online, saying flights "to and from the US" were "subject to disruption".