Each and every country has different taxation. One says you have to only pay taxes as aircrew in the country where the company is based (based meaning all business decision is made, which in case of WZZ is Switzerland). Others base the taxes on residency. A good accountant is a must.
As for my taxes, as I am married, I have to pay around 8% income tax.
The social security contribution in the EU is based on the residency. It also depends on the country, how it is calculated, and how much should be paid.