The aim of this Master thesis is the innovative active monitoring techniques design and developement that reduce the trailing edge high-lift devices asymmetry. Different system failures may cause the control surfaces asymmetry, such as the drive shaft torsion bar braking and the control surface actuators wear and tear. The high-lift system is formed by a Power Drive Unit (PDU) that generates the power transmitted to the reversible actuators by a drive shaft torsion bar. In addition, a wingtip brakes system is implemented to meet the secondary flight controls design requirements considering reversible actuators. The innovative asymmetry active monitoring techniques developed in this project both detect and identify the high-lift device (flap) position asymmetry.