Pilots for the German airline Lufthansa are on a three-day strike stranding almost half a million passengers. It is the biggest strike in the airline's history.
Lufthansa cancelled about 3800 flights on Wednesday, Thursday and Friday as a result of the walkout by pilots who want better pay and retirement conditions. The strike began at midnight and will last until 11.59pm on Friday.
Lufthansa said there would be no talks between the two sides while the strikes were ongoing.
"The economic consequences will be enormous," said head of operations Werner Knorr. "I'm assuming that once the walkouts have ended, negotiations will resume."
In a bid to avert chaos, Lufthansa has been keeping passengers up to date about flight changes via text message or email, and offering to re-book them onto other airlines.
The airline's budget arm, Germanwings, and its freight carrier, Lufthansa Cargo, are also affected by the strike.
However, other subsidiaries - such as Austrian Airlines and Lufthansa Cityline - are not affected.