New York (CNN) — The airline industry has slowly begun to resume service after a Federal Aviation Administration system outage caused thousands of flight delays and cancellations across the United States Wednesday.
The FAA briefly halted all domestic flight departures across the United States Wednesday morning, lifting the ground stop around 9 a.m. ET after it restored a system that provides pilots with pre-flight safety notices.
But airlines continued to delay or cancel flights because of ongoing congestion.
The Chicago Department of Aviation said ground stops at O’Hare and Midway had been lifted but “residual delays or cancellations” are likely.
FlightAware, which tracks delays and cancellations, showed 8,609 flights to, from and within the United States as being delayed as of 3:30 p.m. ET, and 1,258 flights canceled.
Southwest, which canceled thousands of flights after Christmas following a systemwide meltdown, was hit hard, with about 400 canceled flights. About 10% of Southwest flights are canceled and 48% of flights are delayed.
Southwest operations had resumed by mid-morning, the airline said.
American Airlines was hit even harder by one measure: Including feeder airlines that use regional jets, American said it has canceled nearly 400 flights as of midday Wednesday.
Cause of outage still unclear
There is no evidence yet that Wednesday’s air travel technology meltdown resulted from a cyber attack, 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 are also not going rule that out until we have a clear and better understanding of what’s taken place,” Buttigieg said in an interview with CNN’s Kate Bolduan.
A 90-minute nationwide ground stop of flights across the United States Wednesday morning was implemented out of an “abundance of caution.” Buttigieg said that there were “irregularities” overnight in the safety messages that were going out to pilots that reflected a larger issue.
Buttigieg, who has been hard on airlines over their staffing and technology issues in the last year, said the Transportation Department and Federal Aviation Administration would “own” responsibility for their failures.
“No, these kinds of disruptions should not happen and my primary interest now that we’ve gotten through the immediate disruptions of the morning is understanding 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 Wednesday morning there was no immediate information on what had caused the outage — the second US aviation crisis in a matter of weeks.
There is “no evidence of foul play based on our discussions with DOT/FAA,” a senior US official familiar with matter told CNN.
Buttigieg said via Twitter 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. That nearly three-hour outage did not impact 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.
Another aviation meltdown
It’s the second time in less than a month that frequent flyer Erin Potrzebowski has had her Southwest flight canceled as part of mass flight cancellations.
“I’ve never experienced anything like the event today and like the Southwest event from a couple of 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 impact the entire country,” Potrzebowski said.
Calls came swiftly for aviation system upgrades.
“Today’s FAA catastrophic system failure is a clear sign that America’s transportation network desperately needs significant upgrades,” said Geoff Freeman, president and CEO of the U.S. Travel Association.
“Americans deserve an end-to-end travel experience that is seamless and secure. And our nation’s economy depends on a best-in-class air travel system.”
International impacts
International flights bound for the United States were continuing to take off from Amsterdam and Paris despite the situation. A Schiphol Airport spokesperson told CNN that “a workaround had been issued” and flights were still departing from Amsterdam.
No flights have been canceled from Paris’ Charles de Gaulle airport, but delays were expected, according to the airport’s press office. Frankfurt Airport also told CNN it had not been impacted.
A London Heathrow Airport spokesperson told CNN early Wednesday that they were “not aware of canceled flights and that flights to the US had left recently,” however there were passenger reports of significant delays.
Shabnam Amini told CNN that she and other travelers had been sitting on board Americans Airlines flight 51 to Dallas for almost three hours at Heathrow because of the FAA outage.
She said they had been informed that there were delays but were still boarded onto the aircraft.
Commercial airline pilots use NOTAMS for real-time information on flight hazards and restrictions. The FAA stipulates NOTAMS are not to be relied on as a sole source of information, and so some flights may be able to satisfy safety requirements by using other data.
Wednesday’s incident comes on the heels of another aviation crisis. A huge winter storm over the end-of-year holidays caused extensive disruption and helped trigger the Southwest Airlines meltdown that affected thousands of passengers.
While Wednesday’s flight cancellations at Southwest are a problem for its customers, it was nowhere near as bad as what it experienced from December 21 through December 29, when about 16,000 flights, or nearly half of its 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.
