The German service trade union Verdi called for all-day warning strikes on Thursday and Friday for employees in several areas of the Düsseldorf, Hamburg and Cologne/Bonn airports.
The sectors to be affected include the aviation security area, passenger control, personnel and goods control and service areas.
"Longer waiting times or even flight cancellations are to be expected due to the strike," the trade union warned on Tuesday.
The reason for the strikes are negotiations between Verdi and the Federal Association of Aviation Security Companies (BDLS) on time bonuses for night shifts, Saturdays, Sundays and work on public holidays.
Workers are also fighting for a better collective agreement on overtime pay for security and service staff at commercial airports.
A written offer by BDLS was insufficient, the union stressed. Negotiations are expected to continue on April 27 and 28.
