Air Vehicle Design and Technology Considerations for an Electric VTOL Metro-Regional Public Transportation System

This paper examines the potential of VTOL aircraft to supplement commuter rail services in a metropolitan or regional transportation system. An interdisciplinary study was conducted to examine the feasibility of integrating an aerial mass transit system into the existing airspace using a fleet of electrically powered rotorcraft. A notional network of stations and overall operating schedule were constructed based on the existing regional rail networks serving the San Francisco Bay Area. To define the VTOL vehicles, the rotorcraft sizing code NDARC has been modified to accommodate electric propulsion sizing. Initial sizing results indicate that battery technologies available by 2030, coupled with the “shorthop” ranges of the proposed aerial network, result in feasible aircraft designs. These vehicle designs, while significantly heavier than their Jet A powered turboshaft equivalents, may become economically viable in a business environment dominated by fuel costs. Finally, these initial study results are informing follow-on study efforts.