All 108 Tuifly flights scheduled for Friday were cancelled, affecting some 9,000 passengers. As of Friday morning, ten flights had been rescheduled using chartered aircrafts and temporary crews. The company said it is also working to find solutions to bring other holiday-makers back home to Germany, though flight times are subject to change.
But all other flights from Germany, Austria and Switzerland remain cancelled.
“We deeply regret the inconvenience,” the company wrote in a statement.
There may continue to be delays and cancellations over the coming days, and Air Berlin flights may also be affected because a number of Tuifly airplanes have been operated by Air Berlin, crew included.
The German holiday airline has been cancelling dozens of its flights each day throughout this week after numerous staff members called in sick, presumably amid concerns about their jobs and work conditions as Tuifly and Air Berlin negotiate a partial merger.
Air Berlin confirmed on Wednesday that it would discuss transferring part of its fleet to a new group founded by package tour giant Tui and Gulf carrier Etihad.
Tuifly tried to quell staff concerns about the plans by saying in a statement on Wednesday that “existing labour agreements will remain intact” and that the company did not plan to move its base from Hanover.
But the plans have still raised concerns among staff, prompting the mass sick call.
"The airlines have to shoulder the responsibility for the passengers," Transport Minister Alexander Dobrindt told the Bild newspaper. "Internal conflicts must be carried out at the negotiating table and not on the backs of the passengers."
Thousands of passengers on both airlines had to wait for their connections on Thursday, or completely scrap their autumn holiday plans.
According to Philipp Kadelbach from the flight rights advocacy portal Flightright, some 500 people have already demanded compensation for the flight cancellations, and there could be up to 1,000 more to come, he told Südkurier.
But a spokeswoman from Tuifly said that the company would not reimburse travellers.
“The massive and extremely short-notice sickness reports are an exceptional and unavoidable circumstance beyond our control,” she said.
But Flightright said that mass waves of sickness among crew are something that airlines must take into account as part of normal operations.