On September 29, 2016, the four-seat passenger aircraft HY4 took off for the official first flight from Stuttgart Airport. The HY4 is the world’s first four-seat passenger aircraft powered solely by a hydrogen fuel cell battery system. Scientists of the German Aerospace Center (DLR) developed the powertrain of the aircraft and worked together with partners from industry and research in the project.
The HY4 fuel cell aircraft was developed by the DLR Institute for Technical Thermodynamics ( DLR-Institut für Technische Thermodynamik) with its partners Hydrogenics, Pipistrel, H2FLY, the University of Ulm (Universität Ulm) and Stuttgart Airport (Flughafen Stuttgart). DLR scientists were responsible for the development of the hydrogen fuel cell drive and its integration into the aircraft. The powertrain consists of a hydrogen storage, a low-temperature hydrogen fuel cell and a high-performance battery. The fuel cell converts the energy of the hydrogen fuel directly into electrical energy. The only waste product is water. With the electricity thus obtained, the electric motor drives the propeller of the aircraft. The on-board lithium-ion battery provides extra power during take-off and ascent flights. If the hydrogen required for the fuel cell is generated by electrolysis, which uses electricity from renewable energies, the HY4 will fly completely emission-free, not only local. The aircraft is operated by the DLR spin-off H2FLY.
Important step for sustainable aviation
Violeta Bulc, European Commissioner for Transport, said on zero-emission flying:”I am proud thats European researchers and manufacturers have realized this hydrogen fuel cell-powered aircraft, which is a forward-looking activity that embodies the future of zero-emission flying We strongly support initiatives that are fully in line with our new low-emission mobility strategy, which has an important role in bringing people together, connecting large cities and remote locations, and ensuring that businesses grow and develop The EU will continue to support such initiatives to drive innovation. ” Prof. Georg Fundel, Managing Director of Flughafen Stuttgart GmbH, is pleased that the first flight took place at Stuttgart Airport: “Both Stuttgart Airport and aviation in general expect further growth in the future, which is an important reason for us to have an environmentally friendly and perhaps one day even set emission-free flying and innovative technologies. “
Electric Air Taxis in regional transport
“Large passenger aircraft will still be able to fly with conventional power trains for the foreseeable future, but it will be one of the great challenges of the next decades to blow up electromobility and make the air traffic of the future CO2-neutral,” says Prof. André Thess, Leiter of the DLR Institute of Technical Thermodynamics. “Our goal is to further improve the fuel cell powertrain and bring it to life in regional aircraft with up to 19 passengers.”
The electric motor of the HY4 has an output of 80 kilowatts and allows a top speed of around 200 and a cruising speed of 165 kilometers per hour. Depending on speed, altitude and payload a range between 750 and 1,500 kilometers is possible. Striking feature of the HY4 are their two hulls, which are very firmly connected to each other via the wing. In each of the two hulls two passengers have space. The maximum weight of the HY4 is 1,500 kilograms. “With the HY4, we now have an optimal platform to further develop the use of the fuel cell in aircraft,” says Prof. Josef Kallo, head of the HY4 project at the DLR and professor at the University of Ulm. “Small passenger aircraft such as the HY4 can very soon be used in regional transport as electric air taxis and offer a flexible and fast alternative to existing means of transport.”