Hat man am Flughafen als angestellter getrennte umkleiden also frauen und männer getrennt?

As long as there is no mini-airport with a maximum of 9 employees, there should be separate dressings, yes.

ASR A4.1 – Sanitary rooms

4 General

(6) Separate sanitary facilities are set up for female and male employees. In establishments with up to nine employees, separate toilet, laundry and changing rooms for female and male employees can be dispensed with if time-several use is ensured. A direct access between washing and changing rooms is required.