Zonal Safety and Particular Risk Analysis for Early Aircraft Design using Parametric Geometric Modelling

Safety assessment is paramount in aircraft design. For unconventional aircraft or aircraft with novel propulsion or system architectures or technologies, it is critical to investigate safety as early as possible in the design process to eliminate unfeasible aircraft configurations and system architectures. In this context, the Zonal Safety Analysis (ZSA) and the Particular Risk Analysis (PRA) that evaluate the safety aspects from an aircraft configuration and system placement perspective are essential to perform early. These analyses require a three-dimensional (3D) model of the aircraft and systems and substantial manual effort, limiting the ability to perform rapid iterations required to support design space exploration and, eventually, multidisciplinary design optimization. To analyze many aircraft configurations and system architectures, parametric 3D modelling, ZSA, and PRA require automation. This thesis reviews the methodologies for performing the ZSA and PRA from a systems point of view and proposes a novel methodology for semi-automated conceptual-level ZSA and PRA (CZSA and CPRA) implemented using Python and OpenVSP. As part of CZSA, automated aircraft 3D modelling, parametric zone definition, and zone-component interaction analysis methods are developed that are supported by a manually prepared database of safety-driven best practices. The CPRA involves parametric modelling of particular risk threat zones for trajectory-based PRAs and automated detection of system components in these zones. The effectiveness of the proposed approach is demonstrated with case studies for conventional and unconventional aircraft designs and novel system technologies. The presented work is a step towards integrating system safety analysis into multidisciplinary analysis and optimization environments, thus increasing conceptual design maturity and reducing development time

Aircraft system safety : a new approach to assessing in-service performance

Increasingly stringent equipment performance and reliability requirements are being specified to the aerospace industry by aircraft manufacturers, driven by the expectations of both certification authorities and operators. The reality is that aircraft system and equipment reliability in service can fail to meet the design expectations. This thesis details the problem areas within the current analysis process, describing the procedures currently in use and showing what can go wrong. It goes on to propose action that can be taken to ensure safety levels are maintained and details a new approach that is unique to this thesis. The author has devised a new System Safety Compliance Model (SSCM) for ensuring that aircraft system safety standards can be better maintained. Evolved from his earlier highly successful database system at TRW Lucas Aerospace, SSCM will be: - Demonstrably cost effective - A step change in process capability, offering "something new" - Instantly accessible at shop floor level to everyone in the business - Easy to use and as automated as possible to minimise staff training requirement - Capable of performing instant re-assessment of safety performance down to system level and including consideration of a variety of operating environments and conditions - The industry standard repository of component reliability data - "Centrally" owned by a world-wide recognised industry body SSCM is the first system to operate in such a way, and will ensure that the original system safety analysis performed at the design stage, is continually assessed for accuracy throughout its in-service life. If the new methods detailed in this thesis are adopted and acted upon, there is a high probability of a reduction in the risk of aircraft systematic failure in service, leading to increased safety in aviation. The model can be equally applied to other areas of transportations uch as railways