Sidestick priority logic
‐ When only one pilot operates the sidestick, his demand is sent to the computers. ‐ When the other pilot operates his sidestick, in the same or opposite direction, both pilots inputs are algebraically-added. The addition is limited to single-stick maximum deflection. Note: In the event of simultaneous input on both sidesticks (2 °deflection of the neutral position in any direction) the two Max green SIDE STICK PRIORITY lights, on the glareshield, come on and the “DUAL INPUT” voice message activates.
A pilot can deactivate the other sidestick, and take full control by pressing and keeping pressed his takeover pushbutton. For latching the priority condition, it is recommended that the takeover pushbutton be pressed for more than 40 s . The takeover pushbutton can then be released without losing priority. However a deactivated sidestick can be reactivated at any time, by momentarily pressing either takeover pushbutton on either stick. If both pilots press their takeover pushbuttons, the last pilot to press their pushbutton will have priority.
Note: If an autopilot is engaged, any action on a takeover pushbutton will disengage it. In a Priority Situation ‐ A red light will come on, in front of the pilot whose stick is deactivated. ‐ A green light will come on, in front of the pilot who has taken control, if the other sidestick is not in the neutral position (to indicate a potential and unwanted control demand).