Conceptual design studies of vertical takeoff and landing remotely piloted aircraft systems for hybrid missions

Abstract

Spurred by the rapid progress in sensor performance increase associated with contemporary miniaturization, many companies, organizations, and governments are interested in using new opportunities in civil remotely piloted aircraft system applications. Coupled with an enhancement in propulsion system performance as well as an optimized and well-matched aerodynamic design, flight envelope limits can be enlarged and new mission profiles arise. Due to these ambitions, resulting hybrid missions become more complex and individual with partially contradicting demands, such as vertical takeoff and landing capabilities, fast climb and cruise combined with a long-endurance loiter capability, and a hover capability up to altitudes of 5000 m. In order to fulfill the diverse mission requirements, several configuration concepts are investigated. The focus is laid on different propulsion system concepts where various technologies and energy storage types are considered, as well as their effects on the aerodynamic shape and the controllability of the configuration. The investigated concepts comprise tilt propeller, tilt ducted propeller, and tilt wing configurations with fixed and variable pitch propeller. Based on these studies, a feasible concept in the weight category of MTOW ≤150 kg was identified which accomplishes both the aerodynamic and performance demands and the controllability in all flight segments.