Well, it's kinda harder to explain, so i made this neat little drawing, sorry, i'm at my office so i drew it with mouse.
I've got engine jets that are childed to the ship, and they always stay as they are, no matter if the ship moves up or down. What i want is to rotate them slightly when the ship moves up or down, as described in the picture. Now, if it wasn't childed, i could rotate it towards, but as it keeps it's local position, that doesn't work of course.
By the way, i use translate for moving the ship, i don't know what property should i listen to to adjust the rotation of the jet according to the ship movement?