Flights were slowly resuming departures and a ground stop was lifted after the Federal Aviation Administration (FAA) scrambled to fix a system outage overnight that had forced a halt to all US departing flights.
More than 7300 flights were delayed and 1100 cancelled, according to the FlightAware website in the first national grounding of flights in about two decades, industry officials said.
The total was still rising and officials said the outage could cause delays through at least Thursday, if not longer, according to several airlines.
The cause of the problem with a pilot-alerting system was unclear, but US officials said they had so far found no evidence of a cyber attack.
US Transportation Secretary Pete Buttigieg told CNN an issue with overnight “irregularities” with safety messages sent to pilots prompted the outage.
He said the ground stop was the “right call” to make sure messages were moving correctly and there is no direct evidence of cyber attack.
The outage occurred at a typically slow time after the holiday travel season, but demand remains strong as travel continues to recover to near pre-pandemic levels.
The FAA said in a tweet that normal air traffic operations were resuming.
The outage could impact traffic through Friday, said Captain Chris Torres, vice president of the Allied Pilots Association.
“This thing was lifted at 9am Eastern. That doesn’t mean the problem stops at 9am This is going to cause ripple effects,” said Torres, whose members fly for American Airlines.
One issue airlines are facing is trying to get planes in and out of crowded gates, which is causing further delays. Crew time limit rules may also play a factor.
‘Catastrophic’ failure
The FAA had earlier ordered airlines to pause all domestic departures after its pilot alerting system crashed and the agency had to perform a hard reset around 2am, officials said.
Flights already in the air were allowed to continue to their destinations.
A trade group representing the US travel industry, including airlines, called the FAA system failure “catastrophic.”
“America’s transportation network desperately needs significant upgrades,” Geoff Freeman, president of the US Travel Association, said in a statement.
“We call on federal policymakers to modernize our vital air travel infrastructure.”
The outage appeared to have limited impact on transatlantic routes, with European carriers including Lufthansa, Air France, Iberia and British Airways saying flights are continuing in and out of the United States.
Virgin Atlantic cautioned some flights might be delayed.
An operational meltdown at Southwest at the end of last year stranded thousands.
A severe winter storm right before Christmas, coupled with the Texas-based carrier’s dated technology, led to over 16,000 flight cancellations.
The DOT, FAA’s parent agency, criticized Southwest’s failures and pressured the airline to compensate passengers.
Buttigieg rejected the suggestion the FAA should reimburse travelers for delays caused by the FAA issue.
The FAA suffered another significant computer issue on January 2 that led to significant delays in Florida flights.
A total of 21,464 US flights were scheduled to depart Wednesday with a capacity of nearly 2.9 million passengers, data from Cirium showed.