Although Vortex-Ring-State (noted VRS hereafter) is known and has been studied for a long time in the helicopter community, there are still many aspects that raise questions. This is all the more true when considering the many specific features that can be found on the new eVTOL architectures. Their high disk loadings, their distributed lift over numerous rotors on either side of the fuselage and their specific blade control and shapes are just a few of the characteristics that could expose them to the VRS phenomenon with significant differences wrt. conventional helicopters. Moreover, since their purpose is to transport people in urban environments, trajectories will be certainly imposed and the external air conditions (tailwinds, shear or vertical) could prove to be an additional risk factor.
The general first aim of this Action Group chaired by ONEAR and involving 14 partners from France, UK, Italy andGermany is to investigate the potential causes of the Vortex-Ring-State (VRS) phenomenon on new eVTOL aircraft architectures integrating multirotor/propeller systems as well as fixed wings. The resulting potential impacts on the safety and operational characteristics will be considered.
The main objectives of the Action Group will be:
- To enrich knowledge on the risk of VRS in general for aircraft with rotary wings and in particular on the new configurations for Advanced Air Mobility, such as UAM aircraft;
- Potentially provide recommendations for the developers of these new configurations and for certification agencies (EASA, etc.).
