Thanx for the help
no really, i am not mad / annoyed / anything like that, i am in no position to be that

Anyway, i've come up with the solution
Code:

---

while(1)
{
	If (in the air)
	{
		Variable += 0.1 * time_step
	}
	Else
	{
		variable = 0
	}
wait(1)
}
move.z -(variable / ((1 / time_step) * 0.55))

---

i realized that the iverted value of time_step equals how many times bigger the framerate is than 16fps: if the framerate is 160 then 1 / time_step = 10.