Investigation of a Mission-based Sizing Method for Electric VTOL Aircraft Preliminary Design

Future demands for Urban Air Mobility solutions has given rise to electrically powered vertical takeoff and landing aircraft, also known as eVTOLs. The apparent number of these concepts in development has rapidly grown to over 500. The race between eVTOL companies to push their concepts into commercial operation has produced a confidential aircraft development process amongst these manufacturers due to commercial sensitivity. This lack of existing data makes it difficult to carry out conceptual design analysis for eVTOL aircraft. This paper presents the results of the development of a comprehensive mass estimation method for battery-powered eVTOL aircraft in two main configurations, powered lift and wingless. Aircraft component mass estimation methods are adapted from literature on conventional aircraft design synthesis, augmented with rotorcraft power models, which are used to iteratively solve the forward-looking sizing problem using the numerical bisection method. A range sensitivity study showed that for ultra-short missions of 10 km or less, the wingless aircraft becomes more efficient in energy consumption due to its simpler and ultimately lighter airframe structure when sized for very short missions.