(CNN) — Following widespread disruption at US airports due to a failure, the Federal Aviation Administration (FAA) reported that operations have resumed after restoring the system that provides pilots with warnings of pre-flight security Despite the announcement, thousands of flights remain delayed across the country.
“Normal US air traffic operations are gradually resuming following an overnight outage to the Notice to Air Missions system, which provides safety information to flight crews,” the agency tweeted.
Update 5: Normal air traffic operations are gradually resuming across the US following an overnight outage to the Notice to Air Missions system that provides safety information to flight crews. The ground stop has been lifted.
We continue to look into the cause of the initial problem
— The FAA ✈️ (@FAANews) January 11, 2023
The agency issued an order halting takeoffs across the country after detecting a failure in its NOTAM, or Notice to Air Missions, system. Shortly before 9 a.m. ET, the FAA lifted the order, saying air traffic operations were resuming. In that same notice, he said he was still trying to determine what had caused the problem.
The Federal Aviation Administration’s NOTAMS, or Notice to Air Missions, system that failed Wednesday provides pilots with information they should read before they fly.
However, as of Wednesday morning, airlines were still experiencing flight delays or cancellations due to congestion caused by the blackout. A source familiar with the situation said airlines may implement delay programs, which could lead to more schedule problems.
The FAA site still showed an air traffic stoppage at New York’s LaGuardia Airport at 10:05 am ET. The site also showed delays at Charlotte Douglas International Airport in North Carolina, one of American Airlines’ largest hubs.
The Chicago Department of Aviation said operations at O’Hare and Midway have resumed, but there are likely “residual delays or cancellations.”
Airlines for America, an association representing US airlines, said early Wednesday that the outage was “causing significant operational delays.” Major US airlines, including United Airlines, Delta and American Airlines, reported that they had canceled flights as a result of the situation. United Airlines issued a travel waiver for North America.
FlightAware, which tracks delays and cancellations, showed that more than 5,400 flights to, from and within the United States were delayed as of 10:15 a.m. ET, and more than 900 flights have been canceled so far.
Earlier, the FAA had said that “some features are starting to come back online,” but added that it would take time to figure it out. An earlier notice read: “Technicians are currently working to restore the system and there is no estimate for service restoration at this time.”
“We are performing final validation checks and repopulating the system now,” an FAA statement said. “Operations throughout the National Airspace System are affected. We will provide frequent updates as we progress.”
Transportation Secretary Pete Buttigieg tweeted earlier: “I have contacted the FAA this morning about an outage affecting a key system for providing safety information to pilots. The FAA is working to quickly and safely resolve this issue so air traffic can resume normal operations and will continue to provide updates.”
NOTAMS are used by commercial airline pilots to obtain real-time information on flight hazards and restrictions. The FAA stipulates that NOTAMS should not be relied on as the sole source of information, so some flights may satisfy safety requirements by using other data.
The cause of the widespread outage is still unclear
The affected system, Notice to Air Missions (NOTAM), sends alerts to pilots to inform them of conditions that could affect the safety of their flights. It’s different from the air traffic control system that keeps planes at a safe distance from each other, but it’s an essential tool for air safety.
US President Joe Biden said there was no immediate information on the cause of the blackout, the second US aviation crisis in a matter of weeks. He also said that he had been briefed on the issue and that he was in contact with Transportation Secretary Pete Buttigieg.
“I just spoke with Buttigieg,” he told reporters as he left the White House. “They don’t know what the cause is. But I’ve been on the phone with him for the last 10 minutes. I told them to let me know directly when they find out.”
He continued: “They don’t know what the cause is. They hope that in a couple of hours they will have an idea of what caused it and that they will respond at that time.”
Asked if it was a cyberattack, Biden said: “They don’t know. They will find out.”
There is “no evidence of ‘foul play’ based on our discussions with DOT/FAA,” a senior US official familiar with the matter told CNN.
Earlier, White House press secretary Karine Jean-Pierre said in a statement that “there was no evidence of a cyberattack at this time,” but added that Biden had ordered a Department of Transportation investigation.