The Federal Aviation Administration (FAA) halted U.S. departures Friday after telecommunications outages affected air traffic control stability, while Microsoft said it had no indication its services were connected to the disruption.
In a post on X, Microsoft said it had “no indication” its services were related to the nationwide order. The company’s statement described its assessment of the incident.
The FAA’s initial advisory directed airports to hold departing planes for safety and said international arrivals would be handled case by case. The U.S. Department of Transportation (DOT) said intermittent telecommunications outages affected the stability of air traffic control communications and radar systems.
Transportation Secretary Sean P. Duffy said the disruption began at 3:36 p.m. ET Nov. 13. He said overloaded switches and routers in older equipment produced inconsistent data, while newer IP switches remained operational.
Duffy said more than 3,500 aircraft were airborne when the order was issued; the number later fell below 400 as planes landed. A follow-up FAA advisory said the nationwide stop remained in effect, but the air traffic control command center could clear individual departures as facilities recovered.
Duffy announced the airspace had reopened at 8:15 p.m. ET Nov. 13 (01:15 UTC Nov. 14), while warning that flight operations would take time to recover. He also urged Congress to fund modernization of the aging air traffic control network.
The Kyiv Independent reported that the nationwide stop was the first since a 2023 FAA computer malfunction and said the previous nationwide grounding followed the Sept. 11, 2001, attacks.
