Update: FAA lifts nationwide ground stop allowing flights to continue; Lingering delays expected

SAN FRANCISCO — Early morning travelers at San Francisco Bay Area airports were greeted with a rude surprise Wednesday -- monitors filled with flights delayed by a FAA computer outage.

The FAA lifted the nationwide ground hold at 6 a.m., but delays were expected to linger throughout the day.

Among those caught up in the delays was Zac Brown, who was already boarded on his red-eye flight at San Francisco International when the ground stop was declared.

"We were all set to go," he told KPIX. "I feel asleep because that's what you do on an 11 p.m. flight. I woke up nd found out the pilot had come on (the intercom) and said there was an FAA ground stop and all flights in the country had been cancelled."

The FAA issued the following: "Normal air traffic operations are resuming gradually across the U.S. following an overnight outage to the Notice to Air Missions system that provides safety info to flight crews. The ground stop has been lifted. We continue to look into the cause of the initial problem."

Departures resumed at Oakland International Airport at 6:05 a.m., according to airport spokesperson Kaley Skantz. 

She said the ground stop order was lifted before many flights were scheduled to depart and had a minimal impact starting at 5 a.m.

San Francisco International Airport also resumed normal operations just after 6 a.m. Airport spokesperson Doug Yakel said 83 flights were delayed as of 7:22 a.m., which is about 9 percent of all flights at SFO, a figure he said was normal for the airport. 

He also said there were about 20 cancellations Wednesday morning, which he also described as routine and said it was impossible to determine how many were affected by the FAA glitch compared to other factors.

At 4:30 a.m., there were more than 1,200 delayed flights within, into or out of the United States, according to the flight tracking website FlightAware. More than 100 have been cancelled.

Most delays were concentrated along the East Coast, but were beginning to spread west. Inbound international flights are into Miami International Airport continued to land, but all departures have been delayed since 6:30 a.m., said airport spokesman Greg Chin.

The FAA said it was working on restoring its Notice to Air Missions System.

"We are performing final validation checks and reloading the system now," the FAA said. "Operations across the National Airspace System are affected."

The agency said that some functions are beginning to come back on line, but that "National Airspace System operations remain limited."

Transportation Secretary Pete Buttigieg said in a tweet that he is in touch with the FAA and monitoring the situation.

United Airlines said that it had temporarily delayed all domestic flights and would issue an update once it learned more from the FAA.

The FAA is working to restore what is known as the Notice to Air Missions System.

Before commencing a flight, pilots are required to consult NOTAMs, or Notices to Air Missions, which list potential adverse impacts on flights, from runway construction to the potential for icing. The system used to be telephone-based, with pilots calling dedicated flight service stations for the information, but has now moved online.

There is a potential for widespread disruption because of the outage. All aircraft are required to route through the system, including commercial and military flights.

European flights into the U.S. appeared to be largely unaffected.

Irish carrier Aer Lingus said services to the U.S. continue, and Dublin Airport's website showed that its flights to Newark, Boston, Chicago and Los Angeles were running on schedule.

"Aer Lingus plan to operate all transatlantic flights as scheduled today," the carrier said in a prepared statement. "We will continue to monitor but we do not anticipate any disruption to our services arising from the technical issue in the United States."

The FAA said that it would provide frequent updates as it made progress.