USˆˆˆˆ particular, the multi-dimensionality of the parameter space associated with the dynamic response of the aircraft at abnormal conditions exposes the FDI process to specific issues with potential negative impact. Recently, a new concept inspired from the biological immune system was proposed for aerospace systems FDI (19,20) . The Artificial Immune System (AIS)-based fault detection operates in a similar manner to its biological counterpart -according to the principle of self/non-self discrimination -when it distinguishes between entities that belong to the organism (self) and entities that do not (non-self). All appropriate parameters must be identified that are capable of capturing the dynamic signatures of each type of failure considered. Therefore, these parameters characterise/define the 'self' -or normal conditionsand, for that matter, the non-self -or the abnormal conditions. The concept of immunity-based fault detection originates from the idea that an abnormal situation can be declared when a current configuration of 'features' or 'identifiers' matches with a configuration from a pre-determined set -detectors -known NOT to correspond to a normal situation.An integrated set of methodologies for AIS-based detection, identification, and evaluation of a wide variety of aircraft sensor, actuator, propulsion, and structural failures/damages has been developed (21) at West Virginia University (WVU) within NASA's Aviation Safety Program. As part of this effort, the development of an integrated high-performance AIS-based FDI scheme using a hierarchical multi-self strategy is presented in this paper. The scheme is capable of detecting and identifying several categories of sub-system abnormal conditions over an extended area of the flight envelope. The effectiveness of the approach in terms of high detection rate and low number of false alarms for the four categories of failures is tested using data from the WVU motionbased flight simulator. The aircraft model represents a supersonic fighter including model-following direct adaptive control laws based on non-linear dynamic inversion and artificial neural network augmentation (22) .A brief review of the AIS paradigm and its application is presented in Section II. The general framework for the development and testing of the AIS-based FDI scheme is discussed in Section III including aircraft sub-system failure modelling, adaptive control laws, and motion-based flight simulator tests for self definition and performance evaluation. The design of the AIS, including data processing and detector generation and optimisation, is described in Section IV. The design process of the proposed AIS-based FDI scheme is outlined in Section V. Test results, analysis, and evaluation of the FDI scheme performance are presented in Section VI. Finally, some conclusions are summarised in Section VII followed by acknowledgements and a bibliographical list.