Flying in Face of Volcanic Ash: A Reanalisys

Kurzfassung

In April 2010 the Eyjafjallajökull volcano in Iceland erupted and caused the largest breakdown in European civil aviation since World War II. As a result, airspaces were closed by the affected states. In Europe, air space sectors were closed between 15th and 22nd April covering the main period of the crisis. During these eight days, 104 000 flights were cancelled, that is 48% of expected air traffic. Other volcanic events happened in the history of aviation before the well-known eruption in 2010 and afterwards; like airport closures or volcanic ash encounters. Flying during volcanic events is not a rarity; it is a situation every pilot should be aware of. The question, which threshold of volcanic ash concentration or dose is critical for flight safety, is still not answered. It is an ongoing task to reduce the negative impacts of volcanic ash on aviation. The eruption in 2010 motivated the German Aerospace Center (DLR) to start the four-year project VolcATS - Volcanic ash impact on the Air Transport System - in October, 2012. The Institute of Flight Guidance investigated the task of identifying safe routes respecting modeled volcanic ash (VA) clouds. The goal is a flexible air traffic management, which is able to react efficiently in case of volcanic eruptions. We use a simulation-based approach to estimate the impact of modeled volcanic ash zones on European air traffic. Flight trajectories in high accuracy are combined with six hourly VA zones. The impact on air traffic is estimated by determining the duration of trajectory segments that are located within forecasted VA concentrations. Such conflicts are categorized by the phase of flight and show which is most affected, and thus causes flight cancelations. Different strategies were probed to minimize trajectory conflicts with VA; such as horizontal, vertical or temporal conflict resolutions. Further, we allow flight planning through specified VA concentrations as it is possible with a confirmed VA safety risk assessment. The simulation tool Future Air Traffic Simulator FATS by DLR provides a 3D view of the Earth, flight routes and ash zones over time. The scenarios created are conflict-free taking into account both conflicts with surrounding aircraft and conflicts with volcanic ash. This report summarizes the work and results of the Institute of Flight Guidance in the VolcATS project.