Frankfurt - Lufthansa pilots were on strike for a second day on Thursday, grounding Germany's largest airline in a row over retirement conditions.
The pilots announced a three-day stoppage earlier this week, leading Lufthansa to cancel 3,800 flights, or around nine out of ten flights planned for the period.
The action is expected to cost the airline tens of millions of euros and disrupt the travel plans of around 425,000 passengers.
About 700 flights were cancelled for the day in Frankfurt, Europe's third-biggest hub by passengers, and a couple of hundred flights were affected in Munich, airport representatives said.
The pilots are demanding Lufthansa reinstates a scheme that allowed them to take early retirement and still receive a proportion of their pay.
Lufthansa says that now the maximum age at which pilots can still fly has been increased to reflect longer life expectancies, there is no need for the scheme.
There seemed little chance of the sides coming together to end the strike early.
Lufthansa aimed at returning back to normal from Saturday onward, Chief Executive Christoph Franz said in an interview with German daily Bild, adding that for operational reasons irregularities could still occur.
The strike is a boon for Germany's state railway company Deutsche Bahn, which is expecting an extra 20,000 customers a day. It normally transports around 360,000 people a day.