All Departing Flights from the U.S. Temporarily Halted Due to FAA Computer Failure

A computer failure at the Federal Aviation Administration (FAA) caused flights to be halted nationwide on Wednesday, leading to a rapid cascade of hundreds of delays at airports across the country.

The FAA mandated a grounding of all departing flights early Wednesday morning but lifted the order just before 9 a.m. Eastern time after several hours.

Transportation Secretary Pete Buttigieg tweeted that the "FAA has confirmed that the safety system impacted by the overnight failure has been fully restored, and the nationwide ground stop will be lifted immediately. I have initiated an after-action review to identify root causes and suggest next steps."

Before the announcement, delays and cancellations were mounting rapidly, with over 3,700 flights grounded by 8:30 a.m. Eastern time—exceeding the total number of delays for the entire previous day, according to flight tracking service FlightAware. More than 550 flights were canceled, and that figure was rising quickly.

The groundings affected nearly all flights, encompassing both shipping and passenger services.

Over 21,000 flights were planned for departure in the U.S. on Wednesday, primarily domestic flights, with approximately 1,840 international flights scheduled to arrive in the U.S., as reported by aviation data company Cirium.

Certain medical flights were still able to obtain clearance, and the outage did not affect military operations.

What led to the FAA outage?

While the White House initially stated there is no evidence of a cyberattack, President Joe Biden remarked, "we don’t know" and instructed reporters that he has directed the Department of Transportation to look into the cause of the disruption.

President Joe Biden spoke about the FAA situation on Wednesday before departing the White House to accompany his wife for a medical procedure at Walter Reed National Military Medical Center near Washington. He mentioned that he had just received a briefing from Transportation Secretary Pete Buttigieg, who informed him that they still had not determined the cause of the issue.

"I just had a conversation with Buttigieg. They are still unsure about the cause. I spoke with him for about 10 minutes," Biden stated. "I instructed him to keep me updated as soon as they discover what happened... We still don’t know the reason behind it."

Most delays were primarily along the East Coast but were starting to extend westward. Inbound international flights at Miami International Airport continued to arrive, but all departures had been delayed since 6:30 a.m., according to airport spokesperson Greg Chin.

Julia Macpherson was aboard a United Airlines flight from Sydney to Los Angeles on Wednesday when she heard about the potential delays. "While I was in the air, I received news from a friend traveling abroad about a power outage," said Macpherson, who was returning to Florida from Hobart, Tasmania. After landing in Los Angeles, she still has a connection in Denver for her flight to Jacksonville, Florida.

She noted that there had been no announcements regarding the FAA issue during the flight.

Macpherson mentioned that she had already faced a delay in her journey because her initial flight from Melbourne to San Francisco was canceled, prompting her to rebook a flight from Sydney to Los Angeles.

The affected system is known as the Notice to Air Missions (NOTAMs)

The FAA made efforts to restore the Notice to Air Missions system.

Before taking off, pilots must refer to NOTAMs, or Notices to Air Missions, which outline possible hazards to flights, such as runway construction or the risk of icing. This system was previously based on phone calls, where pilots would contact dedicated flight service stations for information, but it has now transitioned to an online format.

As per FAA advisories, the NOTAM system experienced a failure at 8:28 p.m. Eastern on Tuesday, which prevented the distribution of new or updated notices to pilots. The FAA set up a telephone hotline to keep flights departing overnight, but as daytime operations increased, it overwhelmed the backup phone system.

European flights heading to the U.S. seemed to be mostly unaffected.

Irish airline Aer Lingus confirmed that its services to the U.S. were continuing, and Dublin Airport’s website indicated that flights to Newark, Boston, Chicago, and Los Angeles were operating on time.

In a prepared statement, Aer Lingus announced, "We plan to operate all transatlantic flights as scheduled today. We will keep monitoring the situation, but we do not expect any disruptions to our services due to the technical issues in the United States."

This incident adds to the ongoing challenges faced by U.S. travelers, who dealt with flight cancellations during the holidays due to winter storms and technical failures at Southwest Airlines. Throughout the summer, they also encountered long wait times, lost luggage, and delays as travel demand surged following the COVID-19 pandemic, compounded by staffing shortages at airports and airlines in both the U.S. and Europe.