Einfache und quantitative Risikobewertung des Betriebs kleiner unbemannter Fluggeräte im untersten Luftraum

  • Simple and quantitative risk assessment of the operation of small unmanned aerial vehicles in very low-level airspace

Phiesel, Daniel; Moormann, Dieter (Thesis advisor); Eckstein, Lutz (Thesis advisor)

Aachen (2019)
Dissertation / PhD Thesis

Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2019


The increase in the number of unmanned aerial vehicles over the past few years has resulted in a huge interest in effective risk assessment methods for the operation of these new aircraft systems. This is especially true in view of today's standard usage of unmanned aerial vehicles which mainly consists of the operation of smaller devices in very low-level airspace. This paper presents a simple and quantitative approach for the assessment of risks from the operation of small unmanned aerial vehicles (< 25 kg) in low altitudes (< 150 m), based on the risks to persons on the ground (ground risk) and other aviation users (air risk). Furthermore, the risks of operations beyond visual line of sight are considered (BVLOS risk).In contrast to the established qualitative methods within SORA and SORA GER, the operational risks of unmanned aerial vehicles can be more transparently assessed using a quantitative assessment scheme. Here, ground risk, air risk and BVLOS risk are modelled by an addition of safety figures, which directly and comprehensibly reflect the different factors contributing to the risks. In this process the intrinsic ground risk is modelled with only the starting mass of the unmanned aerial vehicle and the density of people in the operating area. Within this framework, today’s common 80 joule rule as a threshold value for the lethal kinetic energy is challenged. At the same time, a model is proposed to determine the risks of high-density road traffic which fits into the general ground risk model. The present work shows that the air risk plays a rather subordinate role in the operation of small unmanned aerial vehicles in a very low-level airspace under certain conditions. This conflicts with the views the traditional risk assessment method in SORA, which can only be resolved by a liberal interpretation of the term Atypical Airspace within the SORA system. Finally, to treat the BVLOS risk adequately, a package of measures is proposed which focuses on the quality of the safety environment, the situational awareness of the remote pilot and other aviation participants as well as the ability to avoid evasion. As an application example, a general permission is proposed for the operation of small unmanned aerial vehicles based on the above-mentioned principles of the present work.