A method for failure detection and isolation for redundant aircraft sensors is presented. The outputs of the concerned sensors are involved in the computation of flight law controls, and the objective is to eliminate any perturbation before propagation in the control loop when selecting a unique flight parameter among a set (generally 3) of redundant measurements. The particular case of an oscillatory failure is investigated. The proposed method allows an accurate fault detection and isolation of erroneous sensor and computes a consolidated parameter based on the fusion of data from remaining valid sensors. The benefits of the presented method are to enhance the data fusion process with FDI techniques which improves the performance of the fusion when only few sources (less than three) are valid.