The Federal Aviation Administration  lifted the ground stop at 8:15pm Eastern time on Friday (01:15 GMT on Saturday), after a telecommunications outage affected the country’s 22 regional air traffic control centres. FlightRadar24 counted more than 4,700 cancellations and 10,000 delays on Friday, with 700 flights already cancelled for Saturday.

At Los Angeles airport, passenger Nicholas Erdodi, who had travelled from New Zealand to attend a conference in Chicago, told Al Jazeera he had spent six hours at the airport after being forced off his plane. “The challenge is you cannot ask anyone here what to do,” he said. “The lack of information is what bothers me.” He had been rebooked, but was unsure whether his next flight would go. Others affected included sports teams in the NBA, NHL and college football.

Todd Curtis, an aviation safety expert and chief executive of AirSafe.com, told Al Jazeera that the failures appeared to be concentrated in the country’s air route traffic control centres. “There are 21 across the United States, one in Alaska and the other 20 in the lower 48”, he said. “These are the folks who handle the aircraft that are transiting from one part of the country to the other, and they rely on multiple handoffs between controllers”.

US Transportation Secretary Sean Duffy said it would “take us some time” to restore capacity and that “we’re going to have some makeup to do”. He acknowledged that tens of thousands of travellers had been stranded, saying he expected operations to be back to normal for the Thanksgiving rush, which begins in less than two weeks.

Cirium, an aviation analytics firm, said about 11,000 flights carrying more than 1.5 million passengers were scheduled to depart US airports after 4pm Eastern time (21:00 GMT), and that at least 827 flights had been diverted by 7:05pm on Friday (00:05 am on Saturday). The Associated Press news agency reported that the shutdown left NBA, NHL and college teams stranded, with NFL teams wondering whether they could travel in time for their games. The Nets were among five NBA teams scheduled to fly on Friday for Saturday games. There are 14 NHL games set to play Saturday.

The San Jose Sharks were left waiting to fly to Utah, while the Florida Panthers reached St Louis before the stoppage. The Texas Longhorns had boarded their plane before it was grounded. “We are grounded and waiting to see when we can leave,” a team spokesman said.

Air Canada said operations would return gradually, with disruption likely on Saturday, and Aeromexico was working to resume operations. In Mexico City, the Benito Juarez international airport said about 70 flights scheduled for Friday could be affected. In Canada, Toronto Pearson said flights that did not need to cross US airspace were operating as normal and that it had increased staffing to support affected passengers. (Aljazeera)