German airline Lufthansa cancelled 1,450 flights after a pilots union called for a strike on Monday and Tuesday, adding to travelers' misery after millions were left stranded by a weekend-long train drivers' stoppage.
Lufthansa said late on Sunday more than 200,000 passengers and two thirds of its scheduled flights - short and mid-length services, mostly within Europe - would be affected by the strike.
Both the pilots' and train drivers' strikes hit at the start of a week-long, half-term holidays in nearly half of Germany's 16 federal states.
"The Vereinigung Cockpit (pilots union) is trying to turn Germany into a standstill nation," the airline said earlier on Sunday.
The union said on Sunday the strike over an early retirement scheme dispute would last from 1100 GMT on Monday until 2159 GMT on Tuesday. Lufthansa's low-cost unit Germanwings is not affected.
If it goes ahead it will be the eighth this year at Lufthansa.