In this paper, we present a robust tracking scheme for an experimental quadrotor, with outdoor real-time implementation. This control scheme is based on the robust structural feedback linearization scheme, presented in [2]. This control scheme has the advantage of combining the classical linear control techniques with the sophisticated robust control techniques. This control scheme is specially ad hoc for unmanned aerial vehicles, where it is important not only to reject the actual nonlinearities and the unexpected changes of the structure, but also to look for the simplicity and effectiveness of the control scheme.