Exploration of a Full-scale Hydrogen Fuel Cell Powered Helicopter through Flight Tests and Analysis

A single pilot, full-scale, proton exchange membrane fuel cell powered helicopter is flight tested with 700 bar compressed gaseous hydrogen as fuel. Models are developed for the fuel cell, hydrogen and the helicopter and validated with flight test data. The data covers powerplant architecture, stack electrical characteristics, hydrogen flow, detailed component weights, radiator drag, and full aircraft power measured in hover and forward fight. The validated models are then used to conceptually explore the conversion of a larger, more capable, turbine engine Robinson R66-like airframe with liquid hydrogen supplied fuel cell. Predictions indicate that payloads of 300−600 lb can be carried over a range of 200 nautical miles with current fuel cell technology if hydrogen storage weight fractions of 0.2−0.3 can be achieved and the tank and baggage compartment both are used for fuel. The key conclusion is that hydrogen fuel cell helicopters are feasible and the test data and validations presented here open the door for advancing its performance in the future.