Originally Posted by
FullWings
I’m pretty sure the Boeing controls, like the autothrottle, are back-driven, not spring loaded. You can pull up a live page that shows the force being applied in each axis.
On the Airbus, with the sidestick in the neutral position, there will be no force on the controls irrespective of speed, attitude, etc.? On the Boeing FBW, if you are out of trim with the controls centred, you will feel a force. It’s also how the envelope protection works in manual flight: you will feel an increasing resistance to your commands (as you would go outside normal limits) but can override this with greater force.
Under normal conditions, the force is applied by a (in some cases mechanical) computer, overriding the springs. Under severe failure conditions, the force might be from springs only.