Thousands of airline passengers were stranded in Germany and around the world after a severed telecommunications cable knocked out Lufthansa’s digital systems, the company said Wednesday, forcing the cancellation of more than 120 flights.
Lufthansa said it had been “affected by an IT outage, caused by construction work in the Frankfurt region,” and urged passengers traveling within Germany to rebook their travel on trains. Frankfurt is Lufthansa’s main hub in Germany and the international airport is the country’s largest.
Hours later, after 4 p.m. local time, Lufthansa said that flight operations
were stabilizing and would continue to improve. For Thursday, the airline said, it expected most flights to be on schedule.
But earlier in the day, Lufthansa apologized to travelers and encouraged them to rebook flights scheduled for Wednesday. Lufthansa passengers at other airports were also affected by the outage, as the disruptions in Frankfurt reverberated throughout the carrier’s network.
Planes that were unable to take off wound up blocking space at the airport’s gates, forcing pilots to divert incoming flights to nearby airports.
Flight Aware, a site that tracks the movement of airplanes, showed that 132 Lufthansa flights, or about one out of five, had been canceled and 202 delayed. More than half of the canceled flights were destined for Frankfurt Airport, leaving passengers who had been booked on those flights stranded.
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Deutsche Telekom, Germany’s main telecom provider, confirmed that a fiberglass cable buried five meters, or more than 16 feet underground, had been severed by a concrete drill during construction work, taking thousands of customers in the greater Frankfurt area offline.
“Our technicians are already on site,” Telekom said in a message posted to Twitter late Tuesday, along with photos showing heavy construction equipment and a tangle of cables. “Due to the significant damage and situation on the site, the repair will be extremely difficult.”
An excavator working in Düsseldorf damaged 17 fiber-optic lines in an single accident on Friday, severing services for thousands of customers, including the state police for North Rhine-Westphalia and Germany’s federal statistics offices, for several hours.
Passengers on Lufthansa who had already checked their luggage and wanted to rebook their travel were stranded without their bags, adding to the delays and difficulties.
Lufthansa is part of the larger Lufthansa Group, which includes Austrian Airlines, Brussels Airlines, Swiss and Eurowings.
Austrian Airlines, based in Vienna, said that the impact to its flights at midday Wednesday was “still minor” although it had suspended all flights to Frankfurt temporarily. Eurowings said it had informed passengers of disruptions, without giving any further details.
Lufthansa wasn’t the only prominent European airline to have technical problems this week. On Tuesday, the Swedish airline SAS, which is a member of the Star Alliance airline network with Lufthansa, reported that its website and app had been targeted by hackers, causing the services to go down for several hours. The company said it was investigating the incident.
“Attacks like this often come in batches, and more attacks are likely to come in the near future,” SAS said in a statement.
There were no indications that the issues at Lufthansa on Wednesday were linked to the cyberattack at SAS.
Germany’s main railway, Deutsche Bahn, was targeted by saboteurs last year who severed overhead cables, disrupting travel across the country and raising concerns about the vulnerability of communications infrastructure.
Lufthansa’s problems come as thousands of ground personnel and air traffic controllers plan to hold strikes at several airports across the country on Friday, including Frankfurt, leaving the country braced for widespread disruptions.
Christopher F. Schuetze contributed reporting.
