braucht man als Stewardess oder Pilot ein Visum?

Yes, of course, like all “normal” travelers too.

However, there are two important differences:

1. The airlines have a department responsible for the issue of visas. You give off your passport and get it a few hours or days later incl. Visa back.

This will also be done if, for example, technicians need to work in a country subject to visa requirements, e.g. a few fan blades or an engine to change. People then need a working visa and that fast. The airline takes care of this.

Two. Almost all flight crews have a second passport, as some countries refuse entry if there are already certain entries in the RP.

Thus, Saudi Arabia does not allow entry with an Israeli visa.