Seven major German airports have been brought to a standstill after hundreds of ground crew walked out on strike in a row over pay.
Aircraft are grounded at Frankfurt, Munich, Stuttgart, Bremen, Hamburg, Hanover and Dortmund.
More than 2,300 flights have been cancelled affecting 300,000 passengers, with air travel effectively wiped-out.
Members of the Ver.di union and Civil Service Association are demanding a 10.5% pay increase for workers.
At Leipzig Airport, a handful of international flights got away this morning but domestic flights were cancelled.
At Frankfurt Airport, a couple of passengers wheeled suitcases through what is usually the bustling departures terminal. It was, one local TV reporter noted, almost as empty as it had been during the Covid pandemic.
The action coincided with the start of the high-profile gathering of world leaders and defence experts at the Munich Security Conference.
The arrival of prominent guests was not expected to be affected but other delegates were advised to travel by train.
Airports handling emergency aid for earthquake victims in Turkey and Syria have said that those cargo flights would continue as scheduled.
But the strike – which comes two days after Frankfurt Airport cancelled 200 flights when building work knocked out Lufthansa’s online check-in and boarding systems – has prompted a furious response from some German business leaders.
Representatives of small and medium business associations condemned the action as unacceptable and accused the unions of taking the whole country hostage for their own interests.
And air passengers in Germany are becoming accustomed – even resigned – to this kind of disruption.
Last summer, staff shortages led to chaotic scenes at airports as flights were delayed and cancelled and travellers queued for hours at check in and security.
A representative for Ver.di said that, unless pay and working conditions improved, those issues would continue and guarantee another turbulent summer at the country’s airports.
Lufthansa has already announced it will have to reduce its summer programme as a result of staff shortages.
Germany’s unions are well organised and it’s rare to see picket lines because most employees participate in strikes. But workers are expected to hold demonstrations at various airports throughout the day.
Their demands have thus far been rejected by employers who are yet to submit their own offer with talks expected to continue next week. And the leader of Ver.di, Frank Werneke, struck a threatening tone earlier.
“The next strikes will have a different dimension,” he said. “Unless the employers table a good offer next week, this will be just a taste of what’s to come.”