FAA system outage causes thousands of flight delays and cancellations

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New York (CNN) – The airline industry is slowly starting to resume service after a Federal Aviation Administration system outage caused thousands of flight delays and cancellations across the United States on Wednesday.

The FAA briefly halted all domestic flight departures across the United States on Wednesday morning, lifting the ground stop around 9 a.m. ET after restoring a system that provides pilots with pre-flight safety briefings.

But airlines continued to delay or cancel flights due to persistent congestion.

As of midday Wednesday, the FAA’s website was still showing ground delays and ground stops at some airports.

Chicago’s Department of Aviation said ground stops at O’Hare and Midway had been lifted, but “remaining delays or cancellations” were likely.

Major US carriers, including United Airlines, Delta and American Airlines, all said they had suspended flights in response to the situation. United and Delta have issued travel waivers in response to the disruption. American Airlines also said its customers could rebook their flights on Wednesday and Thursday at no extra charge.

FlightAware, which tracks delays and cancellations, showed more than 8,100 flights to, from and within the United States as delayed as of 2:15 p.m. ET, and more than 1,200 flights canceled so far.

Southwest, which canceled thousands of flights after Christmas following a system-wide meltdown, was hit hard, with about 400 flights canceled. About 10% of Southwest flights are canceled and 48% of flights are delayed.

Southwest operations had resumed by mid-morning, the airline said.

“As a result of the FAA’s disruption, we anticipate that some schedule adjustments will be made throughout the day,” Southwest said in a statement, encouraging travelers to check their flight status online or via the airline’s app. Southwest has also issued a waiver allowing travelers to change their flights.

American Airlines was hit harder by one measure: Including feeder airlines that operate regional jets, American said it had canceled nearly 400 flights as of midday Wednesday.

The cause of the outage is still unclear

The affected system, Notice to Air Missions (NOTAM), sends alerts to pilots to notify them of conditions that could affect the safety of their flights. It is separate from the air traffic control system that keeps planes at a safe distance from each other, but is another critical tool for air safety.

There is no evidence yet that Wednesday’s air travel technology meltdown resulted from a cyberattack, Transportation Secretary Pete Buttigieg said, but he also wouldn’t rule it out.

“There’s been no direct evidence or indication of that, but we’re also not going to rule that out until we have a clear and better understanding of what happened,” Buttigieg said in an interview with CNN’s Kate Bolduan.

A nationwide 90-minute ground stop of flights across the United States on Wednesday morning was implemented out of an “out of caution.” Buttigieg said there were “irregularities” overnight in safety messages going out to pilots that reflected a larger issue.

Buttigieg, who has been tough on the airlines over their personnel and technology issues in the past year, said the Transportation Department and Federal Aviation Administration will “own” responsibility for their failures.

“No, these kinds of outages shouldn’t happen, and my primary interest now that we’ve gotten over this morning’s immediate outages is to understand exactly how this was possible and exactly what steps are needed to make sure it doesn’t happen again.” Buttigieg said.

US President Joe Biden said on Wednesday morning that there was no immediate information on what had caused the outage – the second US aviation crisis in as many weeks.

There is “no evidence of foul play based on our discussions with the DOT/FAA,” a senior U.S. official familiar with the matter told CNN.

Buttigieg said via Twitter on Wednesday morning that he had ordered an “after-action process to determine root causes and recommend next steps.”

Nav Canada also reported an outage of Canada’s NOTAM system on Wednesday. The nearly three-hour outage did not affect flight operations and its cause is under investigation, the air navigation service provider said.

“At this time, we do not believe the cause is related to the FAA outage experienced earlier today,” Nav Canada said in a statement.

It’s the second time in less than a month that frequent flyer Erin Potrzebowski has had her Southwest flight canceled as part of the mass flight cancellations.

“I’ve never experienced anything like the event today and the Southwest event from a few weeks ago,” said Potrzebowski, who was waiting for a rescheduled flight to New Orleans at Chicago Midway International Airport on Wednesday.

“It’s common to experience weather-related issues, but I’ve never experienced mass cancellations that affect the entire country,” Potrzebowski said.

Calls quickly came for improvements to the aviation system.

“Today’s catastrophic failure of the FAA system is a clear sign that America’s transportation network is in desperate need of significant improvements,” said Geoff Freeman, president and CEO of the US Travel Association.

“Americans deserve an end-to-end travel experience that is smooth and safe. And our nation’s economy depends on a best-in-class air travel system.”

International influences

International flights to the United States were continuing to take off from Amsterdam and Paris despite the situation. A spokesperson for Schiphol Airport told CNN that “a solution has been issued” and flights were still departing from Amsterdam.

No flights have been canceled from Paris Charles de Gaulle airport, but delays are expected, according to the airport’s press office. Frankfurt Airport also told CNN it was not affected.

A spokesman for London’s Heathrow Airport told CNN early Wednesday that they were “not aware of any canceled flights and that flights to the US had recently departed,” however there were passenger reports of significant delays.

Shabnam Amini told CNN that she and other passengers had been sitting aboard American Airlines Flight 51 to Dallas for nearly three hours at Heathrow because of the FAA shutdown.

She said they were informed there were delays but still boarded the plane.

Commercial airline pilots use NOTAMS for real-time information on flight hazards and restrictions. The FAA determines that NOTAMS should not be relied upon as the sole source of information, and thus some flights may be able to meet safety requirements using other data.

Wednesday’s incident follows another aviation crisis. A major winter storm over the holidays caused widespread disruption and contributed to the Southwest Airlines meltdown that affected thousands of passengers.

While Southwest’s Wednesday flight cancellations are a problem for its customers, it wasn’t as bad as the one it experienced from Dec. 21 to Dec. 29, when about 16,000 flights, or nearly half scheduled, had to be canceled due to lack of available staff.

CNN’s Barry Neild, Paul P. Murphy, Betsy Kline, Livvy Doherty, Chris Isidore, Sean Lyngaas, Betsy Klein, Marnie Hunter and Stephanie Halasz contributed to this story.