Originally Posted by Mad Flt Scientist
So a design solution applied is to have an automatic system act to increase the required force - to introduce a degree of "artificial stability" in effect. One way to do this is to have the aircraft automatically "trim the wrong way". that way, when hand flying (and not trimming) you find you have to pull more to slow down (part of the pull is the natural pull the aircraft requires, part is to fight the opposite auto-trim), and similarly push more to accelerate.
Unfortunately these systems are often called things like "auto trim" or have "trim" in their name, and that leads people to sometimes think that their intention is to HELP the pilot trim the a/c, whereas they are designed to do the exact opposite.
Interesting. I've never flown an aeroplane with STS or similar, but I would imagine seeing and listening to the trim wheel spinning of it's own accord, when I'm hand-flying, would be disconcerting. I wonder how it's designed to/does operate during an Unreliable Airspeed event...