The FAA issued a nationwide ground stop to flight operations because the Notice to Air Missions system, or NOTAMs “failed,” impacting flight operations “across the National Airspace System” on the January 11. Technicians reportedly worked to restore it, the FAA said, and eventually it was restored just before 9 a.m.. FAA said the ground stop was implemented “to allow the agency to validate the integrity of flight and safety information.” The White House said in a statement that there was no evidence of a cyberattack but is investigating the cause. The system failed in the early evening hours of Tuesday, January 10, and continued into the morning of January 11. It was not clear what caused the outage of the NOTAM system but “no new NOTAMs or amendments have been processed,” the FAA said. “I have been in touch with FAA this morning about an outage affecting a key system for providing safety information to pilots. FAA is working to resolve this issue swiftly and safely so that air traffic can resume normal operations, and will continue to provide updates,” said Secretary of Transportation Pete Buttigieg. Later Buttigieg tweeted, “FAA has determined that the safety system affected by the overnight outage is fully restored, and the nationwide ground stop will be lifted effective immediately. I have directed an after-action process to determine root causes and recommend next steps.” Around 8:50 Wednesday morning, the FAA tweeted, “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.”