DA-II Electric-Powered Sport Aircraft Utilizing Fuel Cell and Liquid Hydrogen Technologies

The Electric-powered general aviation aircraft, DA-II, represents a major step forward in environmentally friendly vehicle technology. DA-II has been designed to provide clean, quiet, and convenient service for civilian air travel. Electric propulsion was chosen for several reasons. First, by not using an internal combustion engine, the aircraft can greatly reduce air pollution. The electric propulsion is also quiet compared to conventional internal combustion engines. The final reason for choosing electric propulsion is to explore the feasibility of this technology in a commercially viable single propeller aircraft. The basic design philosophy behind the DA-II is to build an easily maintainable, efficient aircraft that could be used in general aviation. Due to its high specific energy density, i.e., the amount of energy stored in a given system or region of space per unit volume or mass depending on the context, a proton exchange membrane (PEM) hydrogen fuel cell system is used as the primary power plant for the DA-II. In order to better understand the design and performance tradeoffs for a hydrogen fuel cell and its feasibility on electric powered aircraft, a conceptual design study of a small-scale aircraft is performed. A propulsion system consisting of a liquid cooled PEM fuel cell with cryogenic liquid hydrogen storage powering a single electric pusher propeller motor is chosen. The aerodynamic configuration consists of a highaspect ratio un-tapered wing and fuselage with single T-tail. Several aircraft design trade studies are done and the most efficient parameters for the DA-II aircraft are chosen. The results showed that the electric powered aircraft is feasible. However, the analysis also showed that a design of an electric powered aircraft using fuel cell energy did not produce the best aircraft design for either long range or long endurance. Technology is still immature for these high expectations. Additional improvements in energy storage density are needed to achieve the performance needed for strong market acceptance.