you know, it's possible only for prop_physiscs and func_physbox, but I wonder if a script would do the trick, thanks to the function "setvelocity".
I want to block something in mid air, but without using other known and impratical tecniques (ex. trigger_vphysics)

Have you tested it before?

You're asking that if you can disable motion in mid-air?
2 questions, what do you want to do it with, and
What script do you want to edit?

Yup, in mid-air (a turret for example).
I'm going to write my script but I'm away from my pc so can't test it right now.

Isn't there a disable motion output for turrets?