Germany's flag-carrier Lufthansa announced it will cancel roughly 800 flights on Friday, impacting about 130,000 passengers, due to a one-day strike by its pilots' union.
"Lufthansa has to cancel almost all flights to and from Frankfurt and Munich for Friday, 2 September," the airline said in a statement, adding that it will have a "massive impact on flight operations in the middle of return season at the end of summer holidays in Germany and other European countries."
By mid-afternoon in Germany, just over 600 flights had been canceled for the day, representing a full two thirds, or 66%, of the airlines' scheduled flights. At the most-affected airports, Frankfurt and Munich, 34% and 27% of the airports' flights have been canceled, according to data from FlightAware.
On Wednesday evening, the Vereinigung Cockpit (VC) union announced that Lufthansa pilots would stage a 24-hour strike starting just after midnight on Thursday after pay talks with the airline had failed. The 5,000-member union is demanding a 5.5% pay rise this year and automatic inflation bumps thereafter.
In late July, the German airline canceled more than 1,000 flights in a week when 20,000 ground staff called a strike.
In its statement, Lufthansa said it "cannot understand" why the union called a strike. "The management has made a very good and socially balanced offer, despite the continuing burdens of the Covid crisis and uncertain prospects for the global economy," said Michael Niggemann, Chief Human Resources Officer and Labor Director of Deutsche Lufthansa AG.
Labor issues have also dogged other European airlines this summer.
In July, Scandinavian Airlines, better known as SAS - the flag carrier of Denmark, Norway, and Sweden - filed for Chapter 11 bankruptcy protection in the United States, one day after a thousand of its pilots called for a strike.
Also in July, British Airways workers called off a planned strike at London's Heathrow Airport after securing an 8% pay increase from management.
And in Spain, cabin crew working for the budget carrier Ryanair have planned weekly 24-hour strikes through January 2023 in an effort to secure better work conditions.
Airlines are also facing labor unrest in the United States.
On Thursday, one of the year's biggest travel days as Americans headed into the long Labor Day Weekend, pilots from airlines including United Airlines, Delta Air Lines and JetBlue Airways picketed at 13 airports nationwide.
These "informational" picketing events took place at airports in Atlanta, Detroit, Los Angeles, Minneapolis, New York, Salt Lake City, Seattle, Boston, Orlando, Las Vegas, San Francisco, Chicago and Washington, D.C.
According to the Airline Pilots Association, the pilots are seeking better working conditions and benefits.