Flights were checked as cancelled’ on a flight information display near Christmas decoration sat the airport in Hanover,Germany, on three days, amid a pilot strike.

German carrier Lufthansa is facing yet another debilitating strike by its pilots, who said they’d walk off the job on Thursday. The strike, which has forced about three-dozen U.S. cancellations beginning Wednesday evening, is the pilots’ second strike this week and the 10th in 2014.

Pilots are upset over Lufthansa’s plans to make changes to its early retirement options. Currently, pilots can retire at age 55 and receive as much as 60% of their pay until they turn 65, when standard retirement benefits begin. German news network Deutsche Welle says Lufthansa “does not want new hires to fall under the plan (and) wishes to increase the early retirement age to 61.” The union wants no changes to the current program.

In fact, the announcement of the new strike comes as pilots already are involved in an ongoing strike that’s scheduled to wind down by the end of Tuesday. That disruption had forced Lufthansa to cancel half of its scheduled flights for Monday and Tuesday, grounding 1,350 flights — nearly half its schedule — and disrupting travel plans of about 150,000 passengers.

The Vereinigung Cockpit union said its latest walk-off would target Lufthansa’s long-haul and cargo flights on Thursday. The union said short- and medium-length flights would be unaffected.

The strike will affect numerous flights to North America. Lufthansa has already released a list of flights that would be grounded by the action. Among its U.S. destinations hit with cancellations for Wednesday evening and Thursday are Atlanta, Boston, Chicago, Dallas/Fort Worth, Denver, Detroit, Houston, New York, Orlando, Philadelphia, Seattle and Washington.

In a statement Lufthansa said it could not afford the current scheme as it faces increased competition from both low-cost rivals in Europe and massive expanding Middle East airlines.