The nonlinear flight dynamics of a rigid body aircraft is stabilized using a modified output feedback linearization control. The perturbations and model uncertainties effects are canceled out by the injection of a compensation term computed by the application of High-Order Sliding Mode Observers-Identifiers. The feedback linearizing controller is designed considering a nominal model of the aircraft dynamic. The resulting controller exhibits a high robustness guaranteeing the stability and maneuverability of the aircraft in the presence of system uncertainties and external perturbations.