Investigation of a mission-based sizing method for electric VTOL aircraft preliminary design

Urban Air Mobility, a recent advance in aviation has birthed electrically powered vertical take-off and landing aircraft, also known as eVTOLs. The apparent number of these concepts in development has rapidly grown to over 250, due to the improvements in battery technologies and distributed electric propulsion (DEP). The race between manufacturers to push their eVTOL concepts into commercial operation has produced a tight-lipped development process amongst these manufacturers. This lack of existing data makes it difficult to carry out conceptual design analysis for eVTOL aircraft. This paper presents a development of a comprehensive mass estimation method towards a higher accuracy in the sizing of eVTOL aircraft configurations. A taxonomy of eVTOL aircraft is created within the major configurations, powered lift and wingless configurations. Using the predicted mass estimate, a detailed component mass estimation adapted from literature on conventional aircraft design synthesis, is carried out and added to the predicted aircraft mass obtained from the mechanistic models. In the sizing process, the residual error in predicted mass is minimized using the bisection numerical method. The iterative process is carried out until a desired level of tolerance is achieved, resulting in the final aircraft mass for the specified configuration.