Originally Posted by
MLHeliwrench
Say the horizontal stab somehow became able to float up and down the screw shaft on its own - would the elevators act as a servo surface like how some aircraft have a smaller flight control surface move opposite the desired deflection of the main surface?
Bear in mind that when the Alaskan MD-80's jackscrew let go, it pulled through the mechanical stop and just kept going. The elevators didn't make a blind bit of difference.