In August 2020, MTU entered into partnership with the German Aerospace Center – DLR, which has been conducting research into hydrogen technology for many years. The partners intend to develop and validate a fuel cell powertrain’s functionality for a Dornier 228 airplane with an electric MTU propeller engine providing over 500 kilowatts of power.
Rolf Henke, DLR executive board member responsible for aeronautics research and technology, said that “this joint research-industry project is the first of many steps toward zero-emission aviation.” MTU chief operating officer Lars Wagner claimed: “As things stand today, fuel cells utilizing sustainably produced hydrogen offer the greatest long-term potential for realizing emissions-free aviation.” Especially true for regional, short- or medium-distance aircraft. The Do-228’s maiden flight could take place in 2026.
Since the beginning of 2020, a 45-member group led by Johannes Hartmann – EXACT, Exploration of Electric Aircraft Concepts and Technologies – has been working on new efficient, eco-friendly commercial airplane technology at the DLR Systems Engineering Institute. Researchers from 20 different DLR organizations aim to bring a 70-passenger aircraft with a 2,000-kilometer range to technological maturity by 2040.
Pascale Ehrenfreund, who left the DLR in late September 2020, originally proposed devising this integrated concept for eco-friendly aviation. It is not clear yet if her successor, Anke Kaysser-Pyzalla (see p. 5), will announce an even more ambitious goal.
“With electrically powered aircraft, an engine’s practical arrangement, distribution and operation must be re-thought from scratch.”
Jan Werner Delfs, DLR Aerodynamics and Flow Technology Institute
HY4 – Tests in Slovenia and Germany
To achieve their goal, EXACT researchers are drawing on expertise in zero-emission aeronautics at the DLR Institute of Engineering Thermodynamics. The institute developed both the Antares DLR-H2 (see HZwei, January 2013) and a four-seat passenger aircraft dubbed HY4, (see H2-international, February 2016 and March 2017). The latter emerged from a collaboration between DLR spin-off H2Fly, Slovenian aircraft manufacturer Pipistrel and Cummins.
A sixth-generation fuel cell engine, powering the latest HY4 model, was designed by Josef Kallo, Ulm University professor, and his team. Despite the difficult circumstances, not least due to Covid-19 regulations, the H2Fly’s plane take-off on Nov. 6, 2020, in Mariboa, Slovenia, was quite a success. Kallo told H2-international: “The system really packs a punch.”
His team’s perseverance kept the project going despite several delays, including the first flight’s postponement from October to November. Following a three-month quarantine, team members completed a total of 32 take-offs in four days in bad, extremely foggy weather with visibility under 1,000 feet (300 meters), sometimes flying for two consecutive hours.
In late 2020, the HY4 received a test flight permit for Stuttgart. Walter Schoefer, Stuttgart airport management company, FSG’s board spokesperson, called it a “great milestone” for the biggest project FSG had ever supported. During the Nov. 11 HY4 presentation at Stuttgart airport, Winfried Hermann, Baden-Württemberg’s state transportation minister and FSG chairman, lauded Kallo and his team for their profound commitment and tenacity.
“HY4 is the future of aviation. […] It shows that flying carbon-free is possible, presently feasible and has what it takes to change transportation in the long term. […] Keep up the good work.”
German transportation minister Andreas Scheuer, via video call
… Read more in the latest H2-International e-Journal, Feb. 2021