Originally Posted by SteamCat
I have never driven an Airbus, but it has been mentioned on here that stick imputs from both sticks simultaneously in some Law conditions results in additive input (ie, if both sticks deflected left, input is doubled, if one left and one right, input is cancelled). Is this true? If so, does it hold for rudder inputs as well?
Side-stick inputs are summed, but limited to the maximum deflection of a single stick. E.g . in roll in normal law, maximum stick deflection demands 15 deg/sec roll rate. If both pilots make full left stick inputs, the demand is still only 15 deg/sec. One pilot making a full left, the other a half-right input, the result would be half-left.
Ruder pedals are different. They are mechanically linked and always control the rudder deflection directly (limited by the travel limiter).
(The rudder is also moved by the FBW system for turn coordination; I am not entirely sure FBW-commanded rudder movements are backdriven to the pedals.)
Bernd