A hydrogen fuel cell-powered aircraft developed by the ENFICA-FC project has completed a number of successful test flights out of Reggio Emilia airport in Italy, establishing new speed and endurance records for electrically powered class C aeroplanes. (Earlier post.)
Separately, the Solar Impulse HB-SIA (earlier post) completed a full day and night flight on solar energy—the longest and highest in the history of solar aviation, as well as the first night flight solely on solar energy.
ENFICA-FC. The goal of the ENFICA-FC project, including ten partners from across the EU, has been to demonstrate manned flight in an electric aircraft using fuel cells as a main power supply. Over three years, it has worked to design, develop and install a fuel cell-based power system in a Czech-built ultra-light aircraft.
The aircraft, called Rapid 200-FC, completed its maiden flight on 20 May 2010, using a completely electrical hybrid power system, comprising a 20 kW PEM fuel cell and a 20 kW Li-Po battery. Test Pilot Marco Locatelli carried out a first aero-mechanical take off, followed by an eleven-minute test flight for investigations of the flight envelope.
Level flight was attained at 700 ft and 130 km/h (70 knots) on a partial fuel cell power setting. Further flight tests were carried out on 26 and 27 May 2010, during which RAPID 200-FC established a new world speed record of 135 km/h (73 knots) for electrically powered class C aeroplanes (four consecutive runs over a 3 km course, as per FAI Sporting Code).
According to Locatelli, the aircraft showed positive handling qualities and satisfactory engine performance. Higher speeds of 145-150 km/h (78-81 knots) were measured for tens of seconds during free flight. The plane also broke the endurance record of 45 minutes.
ENFICA-FC project coordinator Giulio Romeo of the Politecnico di Torino says RAPID 200 FC is one of the first aeroplanes in Europe and in the world to be fuelled by hydrogen. Project partners consider its successful first flights as a major step forward in the introduction of clean energy in aeronautics.
European Commission officials say the ability of low-noise electrically powered commuter airplanes to take off and land on airfields with strict noise abatement regulations in urban areas and near population centres will allow the use of these airfields late at night, when noise abatement regulations are more stringent. This, in turn, will contribute to the more efficient and sustainable use of the aviation system capacity.
The European Union is a strong supporter of research towards more-electric and all-electric aircraft. The primary advantages of electric technologies in aviation include low emissions and low noise, particularly important for commuter airplanes that usually take off and land in urban areas.
Other advantages include lower chance of mechanical failure, such as that caused by volcanic ash, and lower risk of explosion or fire in the event of a collision. The main disadvantages of electric aircraft have been decreased range and weight penalties.
HB-SIA. A total of 11,628 monocrystalline silicon cells (10,748 on the upper wing surface, 880 on the horizontal stabilizer), each 150 microns thick, run four 7.5 kW (10 hp) electric motors and store the solar energy for the night in a 400 kg lithium-ion polymer battery system (25% of the weight of the plane). Each motor is mounted in a gondola beneath the wing which also contains a lithium polymer battery set and a management system controlling charge/discharge and temperature.
The flight lasted 26 hours and nine minutes. Maximum speed was 68 knots (125 km/h), with an average speed of 23 knots (42.6 km/h). Maximum altitude was 8,564 meters (28,000 feet).
The success of this first night flight by a solar-powered plane is crucial for the further course of the project, Solar Impulse said. Now that the HB-SIA’s ability to remain flying at night using solar energy stored during the day has been proved, the next important milestones for Solar Impulse will be an Atlantic crossing and an around the world flight, using a second prototype which goes into construction this summer.