Trade union Verdi said the labour action involved 300 workers and was due to end at 10:30 am. The limited strike was sparked over the British airline's refusal to allow the workers to form a workers' council as is usual in Germany, Verdi said.
The union staged a first warning strike on December 3.
The airline operates flights to more than 30 destinations including London, Paris, Madrid and Rome from Berlin Schönefeld.
Pilots at German carrier Lufthansa voted on Wednesday to stage a four-day
strike from Monday in a dispute over pay and job guarantees.