Following an unprecedented, extraordinary situation that lasted more than four hours, air traffic in the United States is beginning to resume. The U.S. Federal Aviation Administration (FAA) lifted the nationwide ground stop on Friday evening at 8:15 p.m. Eastern Time (2:15 a.m. CET on Saturday). It was the longest total shutdown of American airspace since the terrorist attacks of September 11, 2001. Despite the resumption of operations, airlines and airports around the world are grappling with a massive domino effect this Saturday.
Overloaded routers brought down legacy system
At a White House press conference late Friday evening, U.S. Secretary of Transportation Sean Duffy provided the first concrete details regarding the cause of the outage. According to his account, the interface between outdated analog technology and new digital systems had failed.
Specifically, a system upgrade overloaded older network switches and routers at Air Route Traffic Control Centers with data, causing them to shut down. This resulted in a dangerous instability within the air traffic control system’s radio and radar infrastructure. While ruling out a cyberattack, U.S. official Markwayne Mullin acknowledged that a technical intervention had brought the legacy system to a standstill. According to reports from the financial news service Bloomberg, the FBI is also investigating the precise sequence of events surrounding the software update that was implemented.
The toll of the shutdown: More than 13,500 flights canceled.
Although aircraft are now permitted to take off again, Transport Minister Duffy warned that a return to normal operations would take time. With thousands of planes and their crews stranded at the wrong airports – and flight crews required to observe mandatory rest periods – the wave of cancellations continued unabated on Saturday.
- Record-breaking cancellations in the U.S.: According to the latest data from the flight-tracking service FlightAware, more than 13,500 flights have already been canceled and over 35,000 delayed across Friday and Saturday combined. Major U.S. airlines – including Delta, American Airlines, United, and JetBlue – have been hit particularly hard.
- Stranded travelers: At major hubs such as Atlanta, Chicago, and Las Vegas, tens of thousands of passengers spent the night on cots or the airport floor. In several U.S. cities, demand for rental cars and hotel rooms skyrocketed within a matter of hours.
Impact reaches Frankfurt and Munich
The aftereffects of the US technical glitch are also being clearly felt at German airports this Saturday. During the night, the European air traffic management organization, Eurocontrol, had temporarily halted all departures from Europe bound for the United States. Although Eurocontrol lifted this suspension early Saturday morning, the absence of aircraft arriving from overseas is now causing gaps in European flight schedules.
- Frankfurt Airport: According to a spokesperson, several flights to the United States – including those to Atlanta and Detroit – were initially canceled on Saturday. As early as Friday evening, three aircraft bound for the U.S. had to turn back to Germany.
- Munich Airport: In the Bavarian state capital, several flights were cancelled on Saturday – including two connections to Charlotte and one to Houston – because the aircraft in question had been unable to depart from the United States the previous day.
What affected travelers need to know now
Airports in Frankfurt and Munich, along with the airlines, strongly advise all travelers heading to the U.S. to check their flight status online before leaving for the airport. In the event of a cancellation, airlines are offering free rebooking or ticket refunds. However, because the root cause – an issue within the U.S. government’s air traffic control system – was beyond the airlines’ control, the incident is legally classified as an “extraordinary circumstance.” Consequently, additional compensation under the EU Passenger Rights Regulation is generally not applicable.
