Decarbonization presents a huge technical challenge for the aviation industry – especially for large aircraft and long-haul flights. On an average day, over 100,000 commercial flights take off worldwide – so air traffic is responsible for 2.5 percent of global CO2 emissions caused by humans. As well as sustainable aviation fuel (SAF) and potential alternative fuels for turbines such as hydrogen or liquid methane, development work is under way on electric drives powered by batteries or hydrogen fuel cells. But with longer flight durations and larger passenger capacities, it is becoming increasingly difficult to find adequate replacements for the high energy density of kerosene and aviation gasoline (AvGas).
However, Cellsius – a Swiss team of young engineers – is providing impressive proof that this is already possible for small aircraft and short-haul flights. Founded in 2022 to focus on sustainable aviation, the Cellsius association offers students in their final year of studies for a Bachelor's degree the opportunity to test and expand their knowledge and skills on real aircraft. The Cellsius association's first project – named ‘e-Sling’ – ran from 2020 to 2022. Its objective: to equip a low-wing aircraft with an electric propulsion system. The successful outcome was the world's first licensed four-seater electric aircraft built by students! At an early stage of the project, a torque sensor from Kistler was obtained to assist with designing the motor and developing the power electronics. The sensor is an integral element of the test stand at the Dübendorf site of the Swiss Federal Institute of Technology Zurich (ETH), where the hangars, take-off and landing strips are located. This airfield, now part of the Swiss Innovation Park Zurich, is gradually being expanded to create space for laboratories, workshops, offices and classrooms.