Characterizing The Preturbulence Environment For Sensor Development New Hazard Algorithms And Nasa Experimental Flight Planning

During the grant period, several tasks were performed in support of the NASA Turbulence Prediction and Warning Systems (TPAWS) program. The primary focus of the research was on characterizing the preturbulence environment by developing predictive tools and simulating atmospheric conditions that preceded severe turbulence. The goal of the research being to provide both dynamical understanding of conditions that preceded turbulence as well as providing predictive tools in support of operational NASA B-757 turbulence research flights. The advancements in characterizing the preturbulence environment will be applied by NASA to sensor development for predicting turbulence onboard commercial aircraft. Numerical simulations with atmospheric models as well as multi-scale observational analyses provided insights into the environment organizing turbulence in a total of forty-eight specific case studies of severe accident producing turbulence on commercial aircraft. These accidents exclusively affected commercial aircraft. A paradigm was developed which diagnosed specific atmospheric circulation systems from the synoptic scale down to the meso-y scale that preceded turbulence in both clear air and in proximity to convection. The emphasis was primarily on convective turbulence as that is what the TPAWS program is most focused on in terms of developing improved sensors for turbulence warning and avoidance. However, the dynamical paradigm also has applicability to clear air and mountain turbulence. This dynamical sequence of events was then employed to formulate and test new hazard prediction indices that were first tested in research simulation studies and then ultimately were further tested in support of the NASA B-757 turbulence research flights. The new hazard characterization algorithms were utilized in a Real Time Turbulence Model (RTTM) that was operationally employed to support the NASA B-757 turbulence research flights. Improvements in the RTTM were implemented in an effo

System safety is the application of engineering and management principles, criteria, and techniques to optimize safety within the constraints of operational effectiveness, time, and cost throughout all phases of the system life cycle. System safety is to safety as systems engineering is to engineering. When performing appropriate analysis, the evaluation is performed holistically by tying into systems engineering practices and ensuring that system safety has an integrated system-level perspective.The NASA System Safety Handbook presents the overall framework for System Safety and provides the general concepts needed to implement the framework. The treatment addresses activities throughout the system life cycle to assure that the system meets safety performance requirements and is as safe as reasonably practicable.This handbook is intended for project management and engineering teams and for those with review and oversight responsibilities. It can be used both in a forward-thinking mode to promote the development of safe systems, and in a retrospective mode to determine whether desired safety objectives have been achieved.The topics covered in this volume include general approaches for formulating a hierarchy of safety objectives, generating a corresponding hierarchical set of safety claims, characterizing the system safety activities needed to provide supporting evidence, and presenting a risk-informed safety case that validates the claims. Volume 2, to be completed in 2012, will provide specific guidance on the conduct of the major system safety activities and the development of the evidence.