Flight planning in case of volcanic eruption

Abstract

Within the DLR internal project VolcATS – Volcanic Ash Impact on the Air Transport System- the DLR Institute of Guidance has the task of finding safe routes to deal with volcanic ash clouds. The goal is a flexible air traffic management, which is able to react efficiently in case of volcanic eruptions. Within the project the eruption of Eyjafjallajokull in 2010 is reprocessed. Even before the Eyjafjallajokull volcano erupted there were efforts to keep the impact of volcanic ash on air traffic as low as possible. These efforts have been greatly increased after the eruption. The impacts of this work were already evident during the outbreak of Grimsvotn in 2011. The air traffic had been much less affected in this case. The main focus is the safety of each flight. When spreading volcanic ash threatens aviation, the responsible Volcanic Ash Advisory Center will issue Volcanic Ash Advisories (VAA). The flight planning will then additionally be based on volcanic ash forecasts. These are part of the VAA. The accuracy of sensing and generating the forecasts of volcanic ash has been improved in recent years. The planning of safe flight routes depends on these processes. The forecast of volcanic ash are provided by the DLR Institute of Atmospheric Physics. It has the three zone model for low (0.2 – 2 mg/m³), medium (between 2-4 mg/m³) and high (more than 4 mg/m³) concentrations specified by the Volcanic Ash Advisory Center London [1]. The forecasts are updated in a three hour interval and cover the next 24 hours with three hour temporal resolution. For the air traffic the 17th April 2010 is simulated. On that day the difference between demanded flights and performed flights is significant [2]. Traffic data are downloaded from the DDR of EUROCONTROL. Round trips and flights shorter than 22 NM (these flights will not reach relevant cruise altitudes) are excluded. The resulting scenario contains 22 170 flights within 24 hours. Investigations have shown that most cancelled flights have a conflict during the initial climb phase or during approach to the destination airport [3]. A higher frequency of the forecasts will decrease the number of flights affected at departure or arrival [4]. According to current regulations planning aircraft operations in areas with forecasted volcanic ash are possible if a valid Safety Risk Assessment (SRA) exists [5]. The SRA is valid for one airline. This contribution will take into account this possibility and plan through forecasted zones of low and/or medium volcanic ash concentration. The number of additionally plannable flights is determined. Further, a trial of flight planning with a given volcanic ash forecast and simulating the flights with a poorer prognosis of the volcanic ash dispersal shows if all flights can operate safely in the used simulation environment. Required route deviations and ash cloud avoidance maneuvers are evaluated for that trial. [1] VAAC London, Changes to Ash Concentration Forecasts V12, March 2011, [Online]. Available: Http://Www.Metoffice.Gov.Uk/Media/Pdf/J/3/Changes_to_Ash__Concentration_Forecasts_V12web.Pdf. [Accessed 10 09 2014]. [2] EUROCONTROL, 2010, Ash-Cloud of April and May 2010: Impact on Air Traffic, STATFOR/Doc394 V1.0. [3] Schmitt A.R., Kuenz A., “A Reanalysis of Aviation Effects from Volcano Eruption of Eyjafjallajokull in 2010”, 34th Digital Avionics Systems Conference DASC, September 2015, Prag [4] R. Vujasinovic, a. Kuenz, J. M. Zillies, A. R. Schmitt, C. Edinger and V. Mollwitz, 2013, Optimization of the European Air Traffic during the Grimsvotn Eruption in 2011 Based On Advanced Volcanic Ash Forecast. [5] International Civil Aviation Organization (ICAO), 2012, Flight Safety and Volcanic Ash, EUR Doc 9974 ANB/487, First Edition