The GdF trade union, which represents air traffic controllers in Germany, has called a six-hour strike in a dispute over pay.
The walk-out will start at 6am tomorrow morning (August 4) and end at 12noon.
Airlines are likely to be forced to cancel or delay flights to and from Germany for the duration of the strike.
Lufthansa and Air Berlin have not yet released details of their plans for tomorrow, with the likely outcome to depend on how many take part in the strike.
“We will observe the further development and will make preparations for our customers if necessary,” said Lufthansa in a statement on its website.
Germanwings has rescheduled a number of flights to take off early, before the strike starts – passengers should visit the airline’s website for more details.
In a statement, the carrier added: “If the strike takes place, Germanings would be forced to cancel or delay flights.
“We will only know during the course of the day whether the strike is actually going to take place.”