A new residual analysis approach is proposed in order to improve fault detection performance and robustness. The proposed methodology is based on the Wald's sequential test which assumes that residual signal distribution is Gaussian. The new sequential test overcomes this limitation and allows handling a signal with a Laplace distribution. The proposed approach is applied to the detection of oscillatory failure cases on Airbus A380 elevator actuator. The sequential test is assessed on flight data supplied by Airbus. First results are promising as there is already a noticeable improvement over results obtained with the industrial state-of-practice technique implemented on A380. © 2013 Elsevier Ltd.