A Human Factors Approach for the Analysis and the Encoding of Aviation Accidents and Incidents: A Validation Study

Sharing safety information is a key issue to improve aviation safety. Therefore, it appears necessary to have a common way to describe aviation accidents/incidents in order to get consistent data that will be used to produce relevant safety indicators. This implies to use the same taxonomy, the same compatible software to facilitate data sharing, and, more important, a common method to encode occurrences into safety data. The way human factors are taken into account in the database must be improved since statistics usually provided, deal with accident/incident categories and not with their various causes (most of them are human factors related). The BEA in cooperation with the LAA has developed a methodology for the encoding and the analysis of aviation accidents and incidents. This tool has been successfully used during several investigations but still needs to be scientifically validated. This paper aims at putting safety analysis into perspective. It also discusses the methodology that incorporates the Human Factors SHELL model and a validation study

A Human Factors Approach for the Analysis and the Encoding of Aviation Accidents and Incidents: A Validation Study

Sharing safety information is a key issue to improve aviation safety. Therefore, it appears necessary to have a common way to describe aviation accidents/incidents in order to get consistent data that will be used to produce relevant safety indicators. This implies to use the same taxonomy, the same compatible software to facilitate data sharing, and, more important, a common method to encode occurrences into safety data. The way human factors are taken into account in the database must be improved since statistics usually provided, deal with accident/incident categories and not with their various causes (most of them are human factors related). The BEA in cooperation with the LAA has developed a methodology for the encoding and the analysis of aviation accidents and incidents. This tool has been successfully used during several investigations but still needs to be scientifically validated. This paper aims at putting safety analysis into perspective. It also discusses the methodology that incorporates the Human Factors SHELL model and a validation study

Saturation dependence of the streaming potential coefficient

International audienceObservations of streaming potential for unsaturated conditions do not always show the same trend depending on the hydrodynamic conditions and because of a lake of coherency between the data processing procedures. We combine the data from three studies published in the literature, acquired during non-steady state drainage experiments, and apply the same processing steps. We model the hydrodynamic behaviour of these experiments to confirm that they experienced different flow dynamics. We argue that the raw SP data should not be corrected unless a clear drift of the electrodes stability is observed. The combined hydrodynamic behaviour and the streaming potential response show that (a) the observations of one of the experiment (exp #1) are associated to a limited range of water saturation (0.85-1). The corresponding signals could 16 therefore be fairly modelled assuming no saturation dependence of the SPC whatsoever; (b) the observations of exp #3 led to a SPC that can be larger than its value at saturation; (c) the observations of the exp #2 show a non-monotonous behaviour of the SPC as saturation decreases. The underlying physics of a non-monotonous SPC is related to water/air interfaces as shown by the results of the lattice Boltzmann numerical simulations. The main contribution to the SPC behaviour comes from the charged water/air interfaces and depends on the dynamic state of moving or entrapped bubbles. We finally describe the consequences of such a behaviour on the seismoelectric conversions for unsaturated conditions