Morphing Wing Integrated Safety Approach and Results

Abstract

SARISTU morphing wing is mainly based on three devices: enhanced adaptive droop nose (EADN), adaptive trailing edge device (ATED) and winglet active trailing edge (WATE). All these devices are used together to improve the overall wing efficiency and to reduce the aerodynamic noise. The safety activities described in this paper were performed to verify whether this concept can comply with the standard civil flight safety regulations and airworthiness requirements. The safety analysis was performed in two steps: a functional hazard assessment (FHA) and a system safety assessment (SSA). Both analyses were performed at wing integration level (IS12) and at single morphing wing devices level. A complete mapping between these two levels of analysis was structured from the beginning of the process, starting from the aircraft functional definition, to integrate and harmonize both FHA and fault trees results. FHA was used to assess the severity of the identified Failure Conditions and then allocate safety requirements. Fault tree modelling technique was used to verify the compliance of the system architectures to the quantitative safety requirements resulting from the FHAs. The paper sets out the hypotheses and common data used by the fault trees. A complete but simple example illustrates the safety approach all through the different steps of the safety methodology. Other safety activities commonly performed in the aeronautical field such as the particular risk analysis (PRA), common mode analysis (CMA) and zonal safety analysis (ZSA) were identified in the frame of SARISTU project. This paper concludes with a summary highlighting the main results of these safety activities with some lessons learned from the safety approach adapted to SARISTU context.