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Unmanned aircraft system (UAS) is an emerging technology that is now gaining traction around the world. UAS operations are expected to be integrated into very-low-level rural and urban airspace via the enabling of the novel concept of unmanned traffic system (UTM). For such operations to become a reality, one of the major challenges that needs to be overcome is the assessment and, subsequently, mitigation of safety risk posed to third parties on the ground. Third parties on the ground refer to people or pedestrians that resides within the area of operation but are not involved with the operation. To assess this risk, an approach called third-party risk (TPR) assessment has been developed in many research. Prediction of TPR of UAS operations will allow operators, authorities and stakeholders make well-informed decision on the deployment of UAS operations. If the TPR risk level of the designed operational concept exceeds the acceptable risk level, then risk mitigation can then be applied. In a typical TPR model, one of the important sub-models is the collision consequence model used to predict probability of fatality (PoF) of human subjected to UAS collision. This sub-component requires a good understanding of human fatality due to inflicted injury by UAS collision which is, at this time of writing, still under-studied. This thesis addresses the key component of the TPR framework that is the quantification of UAS collision consequence on human on the ground. The central aim of this thesis is to develop a quantitative, model-based collision consequence model of UAS collision on human. To achieve this main aim, a series of interrelated research studies was performed in a systematic way., Aerospace Transport & Operations

Unmanned aircraft system (UAS) is an emerging technology that is now gaining traction around the world. UAS operations are expected to be integrated into very-low-level rural and urban airspace via the enabling of the novel concept of unmanned traffic system (UTM). For such operations to become a reality, one of the major challenges that needs to be overcome is the assessment and, subsequently, mitigation of safety risk posed to third parties on the ground. Third parties on the ground refer to people or pedestrians that resides within the area of operation but are not involved with the operation. To assess this risk, an approach called third-party risk (TPR) assessment has been developed in many research. Prediction of TPR of UAS operations will allow operators, authorities and stakeholders make well-informed decision on the deployment of UAS operations. If the TPR risk level of the designed operational concept exceeds the acceptable risk level, then risk mitigation can then be applied. In a typical TPR model, one of the important sub-models is the collision consequence model used to predict probability of fatality (PoF) of human subjected to UAS collision. This sub-component requires a good understanding of human fatality due to inflicted injury by UAS collision which is, at this time of writing, still under-studied. This thesis addresses the key component of the TPR framework that is the quantification of UAS collision consequence on human on the ground. The central aim of this thesis is to develop a quantitative, model-based collision consequence model of UAS collision on human. To achieve this main aim, a series of interrelated research studies was performed in a systematic way., Air Transport & Operations

Recent developments in the concept of UAS operations in urban areas have led to risk concerns of UAS collision with human. To better understand this risk, head and neck injuries due to UAS collisions have been investigated by different research teams using crash dummies. Because of the limitations in biofidelity of a crash dummy, head injury level for a crash dummy impact may differ from the human body impact. Therefore, the aim of this paper is to investigate differences in head and neck injuries subject to UAS collision between an often-used Hybrid III crash dummy and a human body. To perform such investigation, multibody system (MBS) impact models have been used to simulate UAS impacts on validated models of the Hybrid III crash dummy and the human body at various impact conditions. The findings show that the Hybrid III predicts similar head and neck injury compared to the human body when UAS collides horizontally from front and rear. However, the Hybrid III over-predicts head injury due to horizontal side impact. Moreover, under vertical drop and 45 degree elevated impact of UAS, the Hybrid III under-predicts head injury, and over-predicts neck injury., Aerospace Transport & Operations, Structural Integrity & Composites, Intelligent Vehicles, Control & Simulation

Evaluating safety risk posed to third parties on the ground due to UAS impact requires a model of probability of fatality (PoF) for human. For quadrotor UAS, the existing impact models predict remarkably different PoFs. The most pessimistic is the impact model adopted by Range Commanders Council (RCC) while the Blunt Criterion model is far more optimistic. The ASSURE study has assessed the third set of PoF values through conducting controlled drop tests of a DJI Phantom III on a crash dummy; these results differ again. To investigate these discrepancies, this paper employs a numerical impact analysis of UAS collisions on humans. The current paper is the third in a series of studies. The first study developed a MultiBody System (MBS) simulation model of a DJI Phantom III impacting the head of a crash dummy; this MBS model has been validated against the experimental drop test results of ASSURE. The second study conducted simulations with the validated MBS model to systematically show the differences in head and neck injuries if the human dummy is replaced by a validated MBS model of a human body. The aim of the current paper is threefold: i) to extend the latter MBS model to assess injury levels for DJI Phantom III impact on thorax and abdomen; ii) to transform the assessed injury levels for head, thorax and abdomen to PoFs; and iii) to compare the MBS obtained PoFs to those from RCC and Blunt Criteria models. The MBS based results show that variations in the scenario of DJI Phantom III impact on the head significantly affect PoF. These variations are not captured by the RCC or BC model, and neither in the ASSURE measurements. Both for head, thorax and abdomen, in case of comparable impact scenarios, the RCC model tends to over-predicts PoF compared to the MBS model, while the BC model tends to under-predict PoF., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Aerospace Transport & Operations, Control & Simulation, Structural Integrity & Composites, Intelligent Vehicles

Recent developments in the concept of UAS operations in urban areas have led to risk concerns of UAS collision with human. To better understand this risk, head and neck injuries due to UAS collisions have been investigated by different research teams using crash dummies. Because of the limitations in biofidelity of a crash dummy, head injury level for a crash dummy impact may differ from the human body impact. Therefore, the aim of this paper is to investigate differences in head and neck injuries subject to UAS collision between an often-used Hybrid III crash dummy and a human body. To perform such investigation, multibody system (MBS) impact models have been used to simulate UAS impacts on validated models of the Hybrid III crash dummy and the human body at various impact conditions. The findings show that the Hybrid III predicts similar head and neck injury compared to the human body when UAS collides horizontally from front and rear. However, the Hybrid III over-predicts head injury due to horizontal side impact. Moreover, under vertical drop and 45 degree elevated impact of UAS, the Hybrid III under-predicts head injury, and over-predicts neck injury., Air Transport & Operations, Structural Integrity & Composites, Intelligent Vehicles, Control & Simulation

Evaluating safety risk posed to third parties on the ground due to UAS impact requires a model of probability of fatality (PoF) for human. For quadrotor UAS, the existing impact models predict remarkably different PoFs. The most pessimistic is the impact model adopted by Range Commanders Council (RCC) while the Blunt Criterion model is far more optimistic. The ASSURE study has assessed the third set of PoF values through conducting controlled drop tests of a DJI Phantom III on a crash dummy; these results differ again. To investigate these discrepancies, this paper employs a numerical impact analysis of UAS collisions on humans. The current paper is the third in a series of studies. The first study developed a MultiBody System (MBS) simulation model of a DJI Phantom III impacting the head of a crash dummy; this MBS model has been validated against the experimental drop test results of ASSURE. The second study conducted simulations with the validated MBS model to systematically show the differences in head and neck injuries if the human dummy is replaced by a validated MBS model of a human body. The aim of the current paper is threefold: i) to extend the latter MBS model to assess injury levels for DJI Phantom III impact on thorax and abdomen; ii) to transform the assessed injury levels for head, thorax and abdomen to PoFs; and iii) to compare the MBS obtained PoFs to those from RCC and Blunt Criteria models. The MBS based results show that variations in the scenario of DJI Phantom III impact on the head significantly affect PoF. These variations are not captured by the RCC or BC model, and neither in the ASSURE measurements. Both for head, thorax and abdomen, in case of comparable impact scenarios, the RCC model tends to over-predicts PoF compared to the MBS model, while the BC model tends to under-predict PoF., Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Air Transport & Operations, Control & Simulation, Structural Integrity & Composites, Intelligent Vehicles

Recent developments in the concept of UAS operations in urban areas have led to risk concerns of UAS collision with human. To better understand this risk, head and neck injuries due to UAS collisions have been investigated by different research teams using crash dummies. Because of the limitations in biofidelity of a crash dummy, head injury level for a crash dummy impact may differ from the human body impact. Therefore, the aim of this paper is to investigate differences in head and neck injuries subject to UAS collision with an often used crash dummy and a human body. To perform such investigation, multibody system (MBS) models have been used to simulate UAS impacts on validated models of the crash dummy and the human body. The findings confirm the moderate risks of head and neck injuries that have been reported. However, neck load differs significantly between the crash dummy model and the human body model, and the human body model sustains larger head injury but smaller neck injury compared to the crash dummy model., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Aerospace Transport & Operations, Structural Integrity & Composites, Intelligent Vehicles, Control & Simulation

Understanding the impact severity of unmanned aircraft system (UAS) collisions with the human body remains a challenge and is essential to the development of safe UAS operations. Complementary to performing experiments of UAS collisions with a crash dummy, a computational impact model is needed in order to capture the large variety of UAS types and impact scenarios. This article presents the development of a multibody system (MBS) model of a collision of one specific UAS type with the human body as well with a crash dummy. This specific UAS type has been chosen because data from experimental drop tests on a crash dummy is available. This allows the validation of the MBS model of UAS impacting a crash dummy versus experimental data. The validation shows that the MBS model closely matches experimental UAS drop tests on a crash dummy. Subsequently, the validated UAS MBS model is applied to predict human body injury using a biomechanical human body model. Head and neck injury from the frontal, side and rear impact on the human head are predicted at various elevation angles and impact velocities. The results show that neck injury is not a concern for this specific UAS type, but a serious head injury is probable., Aerospace Transport & Operations, Structural Integrity & Composites, Control & Simulation, Intelligent Vehicles

The introduction of Urban Air Mobility (UAM) vehicles will initiate many new and unique challenges to the current operational airspace environment. Many of these challenges are researched today, and solutions are investigated. The main goal of this ongoing research is to develop a safe and sustainable UAMsystem looking at the design of vehicles and airspace. However, despite research and testing, it is conceivable that when the UAMvehicles actually become operational, accidents will occur. Here in lies the problem; are accident investigators ready for UAM vehicle accidents? Historically, aviation accident investigations had been reactive and investigation outcomes provided recommendations, which paved the way for incremental safety improvements. Rules and procedures are in place to provide a feedback loop to lower the accident rate and maintain a safe aviation environment in its current form. To establish a UAM safety level, the installation and implementation of technical aids and procedures to assist investigators in future UAM accidents are required. These requirements need to be addressed before implementing a new UAM system in order to provide the required feedback loop to maintain an acceptable level of safety. This paper will address the challenges that future accident investigators will face in a UAM vehicle accident investigation. This paper provides feedback from accident investigation professionals who participated in a prognostic survey to discuss what technical means are required to investigate UAM vehicle accidents. It will provide recommendations to future UAMsystems designers to address and enable accident investigation in order to maintain and enhance the future UAM safety level. The final goal of this paper is to discover potential UAM accident scenarios which may not be immediately apparent to engineers during conceptual design and identify potential design requirements in terms of investigation capability., Structural Integrity & Composites, Aerospace Transport & Operations, Aerospace Structures & Computational Mechanics

Recent developments in the concept of UAS operations in urban areas have led to risk concerns of UAS collision with human. To better understand this risk, head and neck injuries due to UAS collisions have been investigated by different research teams using crash dummies. Because of the limitations in biofidelity of a crash dummy, head injury level for a crash dummy impact may differ from the human body impact. Therefore, the aim of this paper is to investigate differences in head and neck injuries subject to UAS collision with an often used crash dummy and a human body. To perform such investigation, multibody system (MBS) models have been used to simulate UAS impacts on validated models of the crash dummy and the human body. The findings confirm the moderate risks of head and neck injuries that have been reported. However, neck load differs significantly between the crash dummy model and the human body model, and the human body model sustains larger head injury but smaller neck injury compared to the crash dummy model., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Air Transport & Operations, Structural Integrity & Composites, Intelligent Vehicles, Control & Simulation

Understanding the impact severity of unmanned aircraft system (UAS) collisions with the human body remains a challenge and is essential to the development of safe UAS operations. Complementary to performing experiments of UAS collisions with a crash dummy, a computational impact model is needed in order to capture the large variety of UAS types and impact scenarios. This article presents the development of a multibody system (MBS) model of a collision of one specific UAS type with the human body as well with a crash dummy. This specific UAS type has been chosen because data from experimental drop tests on a crash dummy is available. This allows the validation of the MBS model of UAS impacting a crash dummy versus experimental data. The validation shows that the MBS model closely matches experimental UAS drop tests on a crash dummy. Subsequently, the validated UAS MBS model is applied to predict human body injury using a biomechanical human body model. Head and neck injury from the frontal, side and rear impact on the human head are predicted at various elevation angles and impact velocities. The results show that neck injury is not a concern for this specific UAS type, but a serious head injury is probable., Air Transport & Operations, Structural Integrity & Composites, Control & Simulation, Intelligent Vehicles

The introduction of Urban Air Mobility (UAM) vehicles will initiate many new and unique challenges to the current operational airspace environment. Many of these challenges are researched today, and solutions are investigated. The main goal of this ongoing research is to develop a safe and sustainable UAMsystem looking at the design of vehicles and airspace. However, despite research and testing, it is conceivable that when the UAMvehicles actually become operational, accidents will occur. Here in lies the problem; are accident investigators ready for UAM vehicle accidents? Historically, aviation accident investigations had been reactive and investigation outcomes provided recommendations, which paved the way for incremental safety improvements. Rules and procedures are in place to provide a feedback loop to lower the accident rate and maintain a safe aviation environment in its current form. To establish a UAM safety level, the installation and implementation of technical aids and procedures to assist investigators in future UAM accidents are required. These requirements need to be addressed before implementing a new UAM system in order to provide the required feedback loop to maintain an acceptable level of safety. This paper will address the challenges that future accident investigators will face in a UAM vehicle accident investigation. This paper provides feedback from accident investigation professionals who participated in a prognostic survey to discuss what technical means are required to investigate UAM vehicle accidents. It will provide recommendations to future UAMsystems designers to address and enable accident investigation in order to maintain and enhance the future UAM safety level. The final goal of this paper is to discover potential UAM accident scenarios which may not be immediately apparent to engineers during conceptual design and identify potential design requirements in terms of investigation capability., Structural Integrity & Composites, Air Transport & Operations, Aerospace Structures & Computational Mechanics

UAS will be integrated into the airspace in the near future, but the risk of UAS collision is not well understood which hampers the development of adequate regulations and standards. As risk has two constituents: frequency and consequence, collision risk analysis of UAS operations in future UTM asks for a quantitative assessment of various types of frequency and consequence. However, prior to studying such quantitative assessment, it is a prerequisite to identify the various types of collisions and consequences. Doing the latter is the objective of this paper. This paper follows a step-wise approach in identifying the various types of collision consequence under a given UTM ConOps, focusing on the very-low-level UAS operations. The first steps address the analysis of the UTM ConOps, rules, and infrastructure considered, and the identification of types of objects and UASs that will operate in the very-low-level UTM system. The follow-up steps are to characterize impact materials by applying zone of impact analysis, followed by analyzing the types of collision consequence. The result is a systematic identification and characterization of types of collision consequences as well as applicable impact materials and conditions that will form the basis for safety risk analysis in follow-on research., Aerospace Transport & Operations, Structural Integrity & Composites, Control & Simulation

UAS will be integrated into the airspace in the near future, but the risk of UAS collision is not well understood which hampers the development of adequate regulations and standards. As risk has two constituents: frequency and consequence, collision risk analysis of UAS operations in future UTM asks for a quantitative assessment of various types of frequency and consequence. However, prior to studying such quantitative assessment, it is a prerequisite to identify the various types of collisions and consequences. Doing the latter is the objective of this paper. This paper follows a step-wise approach in identifying the various types of collision consequence under a given UTM ConOps, focusing on the very-low-level UAS operations. The first steps address the analysis of the UTM ConOps, rules, and infrastructure considered, and the identification of types of objects and UASs that will operate in the very-low-level UTM system. The follow-up steps are to characterize impact materials by applying zone of impact analysis, followed by analyzing the types of collision consequence. The result is a systematic identification and characterization of types of collision consequences as well as applicable impact materials and conditions that will form the basis for safety risk analysis in follow-on research., Air Transport & Operations, Structural Integrity & Composites, Control & Simulation