This paper presents the problem of robust altitude and attitude trajectory tracking of a tri-rotor Unmanned Aerial Vehicle (UAV) based on a finite-time second order sliding mode control algorithm. The chosen algorithm is a modified super-twisting control with double closed-loop feedback regulation that provides fast finite-time convergence even when the system trajectories are far from the sliding surface, robustness against a wide class of uncertainties and disturbances.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCIA