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The results are presented of a comparative study evaluating the performance of neural network (NN) and fuzzy logic reconstructors (FLRs) for the development of a virtual flight data recorder (VFDK). Typical flight data recorders (FDRS) on commercial airliners do not record the aircraft control surface deflections. These dynamic parameters are critical in the investigation of an accident or an uncommanded maneuver. The results are shown relative to a VFDR based on a neural network simulator (NNS) along with a neural network reconstructor (NNR) or a FLR The NNS is trained off-line, using available flight data for the particular aircraft, for the purpose of simulating any desired dynamic output recorded in current FDRs. The NNS is then interfaced with the NNR or with the FLR. The output of the two reconstructors are the control surface deflections which minimize a performance index based on the differences between the available data from the FDR and the output from the NNS. The study tested with night data from a B737-300 shows that both schemes, the one with the NNR and the one with the FLR, provide accurate reconstructions of the control surface deflections time histories.

This paper presents preliminary results of the development of a virtual flight data recorder (VFDR) for commercial airliners. Federal Aviation Administration (FAA) regulations, currently being revised, mandate the recording of 11 dynamic parameters, not including the control surface deflections. The absence of these data can be critical for crash investigation purposes. This paper proposes the introduction of a VFDR based on a neural network simulator (NSS) and a neural network reconstructor (NNR). The NNS is trained, using flight data for the particular aircraft, to simulate any desired control surface deflections (or any other parameters of interest not recorded by the FDR), minimizing a cost function based on the differences between the available data from the FDR and the output from the NNS. The VFDR scheme has been introduced, tested, and validated with flight data from a Boeing 737-300 with an FDR with extended recording capabilities showing accurate reconstruction of the control surface deflections’ time histories. The VFDR can be considered a tool for crash investigations where control surface failures are believed to be a factor.