Electric flight control system for an aircraft, comprising: - at least one mobile control surface able to be deflected as a function of deflection commands received; - at least one control stick able to be actuated manually by a pilot of the aircraft, the position of the control stick generating first guidance commands representative of the said position; - an automatic piloting device able to automatically generate second guidance commands; and - at least one flight control computer configured to automatically compute control surface deflection commands, with the aid of an integrated computation unit which contains piloting laws, this integrated computation unit using guidance commands to compute these control surface deflection commands, the said guidance commands corresponding to the said first guidance commands during manual piloting of the aircraft and to the said second guidance commands during automatic piloting of the aircraft, the said flight control computer comprising at least one protection module (M1 to MN) for protecting the flight domain of the aircraft defining a protection as a function of a control stick position received during manual piloting, the said protection module (M1 to MN) being able to limit the deflection command transmitted to the control surface, this flight control system being characterized in that it comprises moreover: - a first detection element configured to automatically detect automatic piloting of the aircraft with the aid of the said automatic piloting device; and - an auxiliary element configured to automatically transmit to the said flight domain protection module (M1 to MN), upon the detection of automatic piloting, a predetermined auxiliary position, representing a control stick position equivalent, the said flight domain protection module (M1 to MN) using this auxiliary position as control stick position to implement the protection during this automatic piloting. - at least one mobile control surface able to be deflected as a function of deflection commands received; - at least one control stick able to be actuated manually by a pilot of the aircraft, the position of the control stick generating first guidance commands representative of the said position; - an automatic piloting device able to automatically generate second guidance commands; and - at least one flight control computer configured to automatically compute control surface deflection commands, with the aid of an integrated computation unit which contains piloting laws, this integrated computation unit using guidance commands to compute these control surface deflection commands, the said guidance commands corresponding to the said first guidance commands during manual piloting of the aircraft and to the said second guidance commands during automatic piloting of the aircraft, the said flight control computer comprising at least one protection module (M1 to MN) for protecting the flight domain of the aircraft defining a protection as a function of a control stick position received during manual piloting, the said protection module (M1 to MN) being able to limit the deflection command transmitted to the control surface, this flight control system being characterized in that it comprises moreover: - a first detection element configured to automatically detect automatic piloting of the aircraft with the aid of the said automatic piloting device; and - an auxiliary element configured to automatically transmit to the said flight domain protection module (M1 to MN), upon the detection of automatic piloting, a predetermined auxiliary position, representing a control stick position equivalent, the said flight domain protection module (M1 to MN) using this auxiliary position as control stick position to implement the protection during this automatic piloting. - a first detection element configured to automatically detect automatic piloting of the aircraft with the aid of the said automatic piloting device; and - an auxiliary element configured to automatically transmit to the said flight domain protection module (M1 to MN), upon the detection of automatic piloting, a predetermined auxiliary position, representing a control stick position equivalent, the said flight domain protection module (M1 to MN) using this auxiliary position as control stick position to implement the protection during this automatic piloting.