The trend is to replace the hydraulic actuators by electromechanical actuators (EMAs) in aviation. This structural change would allow cancelling the overall hydraulic circuit on board and thus decrease the maintenance needs, the energy consumption and the aircraft weight. MONISA aims at designing, implementing and validating a monitoring system for EMAs used in aircraft flight surface control. Such a system will allow keeping an identical level of safety and availability for the EMAs as for hydraulic actuators by following their health status. It should be able to detect in a premature way any fault occurrence on the EMAs and follow its temporal evolution. In that way maintenance operations can be performed in due time to avoid that the degradations lead to a functional failure of the actuator. Furthermore, the monitoring system must have a very low false alarm probability in order not affect aircraft availability.