Thomas Winkelmann claimed the move by almost 200 pilots to call in sick at short notice was "the equivalent to playing with fire" and would cost the troubled airline "several million euros".
It seems like sickness is in the air since their cancelled flights aren't.
Earlier in the day, the airline said that its pilots had filed an unusually high number of sick leaves, and it was forced to cancel flights.
"This day is costing us several million euros", Winkelmann said in a statement.
Air Berlin filed for bankruptcy protection last month after its biggest shareholder, Etihad Airways, withdrew funding following years of losses. "That is crucial in order to bring talks with investors to a successful conclusion", Chief Operations Officer Oliver Iffert said in an internal memo. "This is the only way we can protect as many jobs as possible".
Will Stephen King's 'It' invade your nightmares? - Lake County Record-Bee
Back in August, the film was tracking well and box office estimates were tallied at between $50 and $60 million for its debut . Firstpost - 4 Stars: When first class story material meets first class execution, you get films like Andy Muschietti's It.
"We are in the middle of final negotiations with potential investors".
Air Berlin has announced it will end long-haul flying, which many crew regard as the best option - it offers higher earnings and, for some, a better lifestyle.
Pang previously acquired the former German military airport Parchim, located between Berlin and Hamburg.
The airline has experienced financial difficulties for years, and it's only operating by a Government loan.
Pilot union Vereinigung Cockpit says it is "surprised" by the cancellations and stresses that it has not called on its members to call in sick.
"The fear and anger among Air Berlin staff is escalating because the future of whole families are at stake".