Development And Flight Testing Of A Hydrogen Fuel Cell Powered Helicopter UAV

Abstract

This paper presents the design, development, integration, and flight testing of a hydrogen fuel cell-powered hybrid propulsion system for the AREA UAV, a battery-electric powered unmanned helicopter with intermeshing rotors, developed at the Technical University of Munich. To extend the flight endurance beyond the 20-minute limitation of battery-only operation, a hybrid energy system combining proton-exchange membrane (PEM) fuel cells with lithium-polymer batteries was developed. The system was initially sized using NDARC simulations and refined based on component availability and safety considerations. Ground-based testing validated subsystem performance, including fuel cell characterization, hybrid battery evaluation, and dynamic load testing of the full powertrain. A calibrated fuel cell model was derived from test data to assess system efficiency, with measured hydrogen consumption yielding an overall mission efficiency of 46.1%. Following successful integration, flight tests were conducted in hover-out-of-ground-effect conditions, demonstrating sustained power output exceeding manufacturer specifications and confirming the feasibility of longer than one-hour missions with the installed 380 g hydrogen capacity. The results demonstrate the viability of hydrogen-electric propulsion for small VTOL UAVs and provide valuable insights for future development of sustainable rotorcraft systems.