"Air Safety Investigation – The Journey" is an introductory book that explores the world of air safety investigation. Unlike a how-to manual for investigating aviation accidents, this book focuses on the essential knowledge and mindset required to conduct a safety investigation. It covers the various phases of an investigation, from gathering facts to formulating safety recommendations, with each chapter addressing a different relevant aspect. With the increasing complexity of investigations, critical thinking, logic, and speculation are essential skills for investigators to possess. This book delves into these topics, offering thought-provoking examples and questions to address the challenges of drawing conclusions and obtaining positive investigative outcomes. Its aim is to help students and readers interested in air safety develop the necessary mindset and knowledge to conduct an investigation. By the end of the book, readers will gain a deeper understanding of the complexities involved in an air safety investigation.@en

The Faculty of Aerospace Engineering at the Delft University of Technology has an active learning philosophy which is embedded in its curriculum. The first year project Design and Construction is run in the second semester. The course aims to provide “hands-on” experience to students in design and construction. Applying knowledge from courses and developing interdisciplinary (soft) skills. A total of 400 students are divided into 40 groups of approximately ten students which are given several design challenges during the project. At the end of the project a final design challenge is given to build and test an aluminium wing design. In March 2020, half-way through the project, the Dutch government announced a nationwide lockdown which resulted in the University being closed to students and the remainder of the academic year being offered online. This paper will reflect on the challenges, solutions and online experience of the project and examines the on-campus v.s. online experience. The conclusion can be drawn that the learning objectives can be reached both on-campus and online. As was found in previous studies, online requires a common collaboration program and more structure to meet or exceed on-campus education. There is an advantage for online looking at the student grade data.@en

With the rising number of Unmanned Aerial Systems (UAS) flying in the sky, an increase in collisions with manned aircraft seems inevitable. Since these devices are permitted to operate in airspace which they share with rotorcraft, a helicopter is certainly not retained from the risk of colliding with a UAS. The only prevailing impact related certification requirement for rotorcraft is the §29.631, which is only applicable to all larger (Part 29) rotorcraft. This requirement states that the rotorcraft must be capable of safe continuation of the flight and/or safe landing after an impact with a 1 kg bird up to the rotorcraft’s maximum horizontal velocity. In this paper, simulations have been performed in explicit Finite Element software to assess how much damage a Part 29 compliant helicopter would sustain after colliding with a UAS. For this purpose, an Agusta A-109 helicopter windshield was impacted by a DJI Phantom III quadcopter UAS under various conditions. The results of the simulations showed that the windshield would sustain severe damage after the impact. Not only would the windshield break into dangerous fragments that could enter the cockpit, parts of the UAS would also penetrate the windshield. These items could strike the crew and a safe continuation of the flight and/or safe landing following the impact cannot be guaranteed. A similar level of safety compared to the bird strike requirement in the prevailing certification requirement is therefore not assured.@en

On the 15t hof December 1965 the motion picture “Flight of the Phoenix” was released in the United States of America theatres. In the closing movie credits the following text is shown:It should be remembered. . . that Paul Mantz, a fine man and a brilliant flyer gave his life in the making of this film. Who was Paul Mantz? What happened? And what can we learn from a movie crash? This paper will examine the Tallmantz Phoenix P-1 accident which was captured on film for the motion picture “Flight of the Phoenix”. This paper will study the “Flight of the Phoenix“ story, the people involved and the special purpose aircraft build. Literature will be reviewed and analyses will be done to gain new insights to the crash of the Tallmantz Phoenix which occurred on July 8th1965@en

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.

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This year, 2020, the Faculty of Aerospace Engineering at Delft University of Technology in the Netherlands celebrates its 80th birthday. This paper describes the history of the department since its founding in early 1940, just before the start of World War II in the Netherlands, until present day. The paper will highlight how its research and education developed within the socio-economic context of the Netherlands and the developments in aerospace over the past 80 years.@en

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.

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This year, 2020, the Faculty of Aerospace Engineering at Delft University of Technology in the Netherlands celebrates its 80th birthday. This paper describes the history of the department since its founding in early 1940, just before the start of World War II in the Netherlands, until present day. The paper will highlight how its research and education developed within the socio-economic context of the Netherlands and the developments in aerospace over the past 80 years.@en

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. @en

Today’s aircraft are equipped with multiple sensors, which monitor the integrity of aircraft systems and support predictive maintenance to increase aircraft operability and safety. Although the tires are only functional in a small time frame during flight, tire failures can have a huge operational impact on both the aircraft and airport. The Airbus Global University Partnership Program (AGUPP) has the objective and vision to foster relationships between Airbus and partner universities. One of the axes clearly identified within AGUPP is providing universities and students access to the means and facilities within Airbus. Following the AGUPP in 2017 call Delft University of Technology pitched the idea to a determine tire wear using a laser profilometer to Airbus. The idea was accepted, and for the project access to Airbus test facilities were granted with a tight time schedule and technical constraints. Having strict deadlines and short time periods where test facilities would be available meant that an iterative test development process was required to stay on schedule. The developed laser profilometer to measure main landing gear tire wear needed to be tested before being integrated into the Airbus A350 flight test aircraft and the Airbus Test Rig for Aircraft Tyres (TeraTyre) facility. The technical constraints set by Airbus was that the profilometer system should be stand-alone and not interfere or damage test facilities. These two technical constraints influenced the design and implementation of the laser profilometer system. This paper will provide a development overview of the laser profilometer system. Furthermore, preliminary results of the laser profilometer data which was gathered during ground tests will be presented. @en

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.@en

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.@en

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.

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Based on established theories from literature and best practices of forensic investigations in aerospace engineering, civil engineering and biomechanical engineering, the Delft University of Technology has developed a Delft approach
for forensic investigations. This integrated approach consists of three elements. First, because a product has a life cycle with various phases, it is of importance to consider these phases when a failure is investigated. Second, it is
acknowledged that failure is a multifaceted phenomenon. Therefore, the ‘Tree House of Failures’ was developed, a taxonomy or categorisation of failure causes, which addresses main groups of causes of failure related to product,
instruction and execution. Third, use of a standard investigative approach with the steps ‘orientation’, ‘data collection’, ‘hypotheses generation’, ‘hypotheses testing’, ‘recommendations’ and ‘findings reporting’ is advised. In the Delft approach, the ‘ring of trustworthiness’ is used to underline the mind-set that a forensic engineering investigator should have to assure the investigation’s reliability and validity. The ring of trustworthiness states that an investigation should be objective, repeatable, verifiable, complete and correct. This paper presents the Delft approach for forensic investigations and explains how to use it to prevent several common pitfalls and biases that occur in various stages of a forensic engineering investigation. This approach aims to increase the reliability of forensic engineering investigations worldwide.@en

Historical research is defined as the process of critical inquiry into past events to produce an accurate description and interpretation of those events. While using different information sources an attempt is made to reconstruct what happened during a certain period of time as completely and accurately as possible. The purpose of historical research is to make people aware of what has happened in the past in order to, for example, to learn from past failures and successes and apply them to present-day problems. Historical research is similar to Forensic Engineering which tries with the application of engineering principles to investigate failures with the goal to understand and prevent future events. An interesting example is the B-17 “Flying Fortress” bomber. Despite setbacks and crashes of the prototypes, it eventually became the iconic bomber ofWorldWar II. Nearly 13,000 bombers were built and a few of them are still flying today. During its operational service above the European theater in World War II the B-17 was hit and damaged many times. In some cases, an aircraft could return to its home base, in other instances, the damage was too great and the aircraft crashed and was destroyed. The focus of this paper is an accident which happened on May 19th 1944, when the left horizontal stabilizer of a B-17 was hit by a bomb dropped from another B-17 flying in formation above. This event was captured by a camera located behind bomb bay which show the sequence of events in several photographs. Historical background information about the B-17 will be used to understand how it was designed with emphasis on the horizontal stabilizer. Using a forensic engineering perspective, this information will be used to understand and attempt to explain what happened. The B-17 stabilizer bomb impact event is part of an ongoing research project. @en

In this paper, the transition from teaching on-campus to an online audience consisting of working professionals in an Aerospace Engineering context is described. The differences in the learner’s needs and the transition in teaching methods and style that is required from teaching staff is discussed. This is illustrated by two case studies: for Smart Structures and for Air Safety Investigation. Recommendations on how universities can contribute to Life Long Learning are given.@en

A serious incident occurred at Eindhoven Airport (Netherlands) in May 2013. A Boeing 737-800 performed a go-around while using the Instrument Landing System (ILS). The flight crew reported a False Glide Slope capture as the reason for the go-around. At first the occurrence report did not really gain much attention but when the investigation progressed it turned out to be a safety deficiency on a global scale. Following flight tests it was found that a potential serious weakness in the automatic systems and logic used was discovered that effected many aircraft types and perplexed many pilots in the past. The Dutch Safety Board finalised the investigation with recommendations in two Final Reports. The first report deals with the event ”Stick shaker warning during ILS approach Eindhoven Airport” and a second report, “Pitch-up Upsets due to ILS False Glide Slope”, deals with the explanation of the pitch-up response of aircraft on a global scale.@en