“We had 20,000 passengers stranded in Copenhagen on Monday alone. This strike has hit us hard financially,” SAS spokesman Bertil Ternert told AFP.
About 150 SAS pilots in Copenhagen have refused to go to work since early on Monday in protest against job cuts and alleged worsened working conditions.
The Danish pilots are opposed to management plans to move their contracts to the local SAS-Denmark company from the Scandinavian umbrella group, something they say would weaken their employment conditions and salaries.
In Oslo meanwhile, about 100 pilots from the Norwegian branch of SAS, SAS-Braathens, have called in sick since Monday in what is thought to be a solidarity action with their Danish colleagues.
The lawsuit by SAS has been filed against all three Scandinavian pilot unions but targets the SAS pilots in Denmark in particular.
“We want the Labour Court to order our employees in Denmark to return to work,” Ternert said.
The court was expected to fast-track the case and present its ruling later on Wednesday.
Hundreds of flights have been cancelled out of Oslo and Copenhagen and disruptions continued on Wednesday.
Employees in Norway are allowed to take up to eight days off for medical reasons without having to provide a doctor’s note, but management of SAS-Braathens signalled on Wednesday that the company would no longer accept sick notice from pilots without medical documentation.
SAS-Denmark has estimated that the strike, which it has called “illegal” and “unacceptable”, is costing the company up to 25 million Swedish kronor in lost revenues per day.
Ternert said SAS was suing the pilot unions because they “have a responsibility to make sure that the collective branch agreements are respected”.
The wildcat strike “is a clear violation of the collective agreements,” he said.
SAS has also demanded compensation of 10,000 Swedish kronor from each of the pilots.
In Copenhagen, most of Wednesday’s flights have been cancelled and it is not known when the pilots will return to work.
The wildcat strike comes after the airline cancelled hundreds of flights out of Copenhagen at the weekend owing to heavy snow and extreme cold, wreaking havoc for tens of thousands of passengers.