US flights resume after nationwide ground stop, with delays set to outlast the outage
The FAA lifted its departure halt on Friday evening after air traffic control communications became unreliable. Airlines faced the separate job of rebuilding their schedules.
US airports began sending flights out again on Friday evening after the Federal Aviation Administration lifted a nationwide ground stop. Transportation Secretary Sean Duffy said departures were cleared to resume at 8:15pm Eastern time on 13 November, or 1:15am Saturday in Britain. The restart ended a halt triggered by communications problems at multiple air traffic control centres. It left airlines with cancelled departures, displaced aircraft and crews who were no longer where the timetable needed them.
What controllers saw
Duffy told a White House briefing that radar and communications became unstable at 3:36pm Eastern time. The problems appeared in centres that handle aircraft travelling between regions and at facilities that manage approaches and departures around airports. Controllers continued handling flights already in the air while the departure halt limited the number of aircraft entering the system. The FAA’s initial statement described its information as preliminary and said technicians were investigating.
The Department of Transportation described intermittent telecommunications outages. Duffy said older switches and routers became overloaded and began delivering inconsistent data. He said newer internet-protocol switches that had already replaced some equipment stayed in service. That is the administration’s initial account. The FAA’s published statement gave no technical sequence showing how the trouble spread between facilities.
The restart at the airports
Associated Press reported that aircraft were diverted to airports including Chicago O’Hare, Denver and Ronald Reagan Washington National. Airlines also had to account for disruptions beyond domestic routes. AP reported that Air Canada cancelled flights between Canada and the United States and warned that other services using US airspace could be affected. Reuters reported thousands of cancellations and delays, citing flight-tracking data. Duffy said the pace of the restart would depend in part on which crews were available to fly.
Analysis — Getting the timetable back in place
A nationwide halt creates a different recovery problem from a closure at one airport. A plane that lands somewhere other than its intended destination can leave one airport accommodating an unexpected arrival and the other waiting for the aircraft it was due to send on its next trip. Crews also have limits on how long they can work, so a delayed departure may have to wait for a replacement crew even when the aircraft is ready.
The outage also raises a question about how failures move across a network. The immediate test is whether flights can run reliably through the next day of operations. The longer-term question for the FAA is which parts of the system shared the failing equipment or connections, and whether those parts can be isolated so a similar fault affects fewer airports.