U.S. Transportation Secretary Pete Buttigieg commented on flights delays after a key aviation warning system went down.
The Federal Aviation Administration grounded all flights early Jan. 11, after its Notice to Air Missions (NOTAM) system failed. The rolling flight grounding began shortly before 4:18 a.m. ET, when the nation's Air Traffic Control System Command Center announced the NOTAM System Failure.
"Safety is always our first priority, and ensuring flight safety was the reason for this morning's ground stop while the affected systems were restored and checked," Buttigieg said in a Twitter post. "As normal flight operations have resumed, FAA continues to assess the causes of the outage."
As stranded passengers crowded airports nationwide, FAA issued several NOTAM statements. In that first statement, FAA announced it was trying to fully restore the system outage and that ground stops would continued until 9 a.m. "to validate the integrity of flight and safety information."
The NOTAM system alerts pilots of real-time weather data and other safety alerts, according to the FAA website.
"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," Buttigieg said in a Twitter post just before 9 a.m. "I have directed an after-action process to determine root causes and recommend next steps."
By 8:50 a.m., normal operations were resuming, according to the FAA statement. Departures were resumed at Newark Liberty and Atlanta Hartsfield-Jackson airports had been cleared by 8:15 a.m.
Buttigieg also tamped down rumors the outage was caused by bad actors, according to an MSNBC report.
"There is no direct indication of any kind of external or nefarious activity, but we're not yet prepared to rule that out," Buttigieg told MSNBC.
"The FAA is continuing a thorough review to determine the root cause of the Notice to Air Missions (NOTAM) system outage," FAA said in its final statement of the day. "Our preliminary work has traced the outage to a damaged database file. At this time, there is no evidence of a cyber attack. The FAA is working diligently to further pinpoint the causes of this issue and take all needed steps to prevent this kind of disruption from happening again."
"At my direction, FAA is continuing its system review," Buttigieg said in a later Twitter post. "Preliminary work has traced the issue to a damaged database file, with no evidence of a cyber attack. FAA will continue its work to further pinpoint the sources of this issue and steps to prevent it from occurring again."
NPR cited the tracking site FlightAware and reported 6,988 flights in, out and around the country had been delayed, and that just more than 1,100 had been cancelled.
