MAHEPA’s goal is to demonstrate and showcase technologies that can produce long-endurance, zero-emission flights using hydrogen or alternative fuels. The initiative is part of the European Green Deal, a program established by the European Union. A MAHEPA statement said that the Hy4 flight showed that the aircraft’s powertrain was capable of upgrading to the megawatt level, which would ultimately support the goal of powering air taxi, general aviation, and regional aircraft of “up to 40 seats and a range of 2,000 km [about 1,080 nautical miles].” MAHEPA said that the Hy4 is “the most powerful hydrogen fuel cell driven aircraft ever made.”
Support for the Hy4 comes from the European Commission, the German Federal Ministry of Transport and Digital Infrastructure, the German state of Baden Württemberg, the Stuttgart airport, and other agencies.
If the odd-looking Hy4 design seems familiar to those following trends in electric aviation, it’s because Pipistrel Vertical Solutions was the lead firm behind the aircraft. The Hy4, with its twin fuselage booms, twin empennages, and centrally mounted motor, closely resembles Pipistrel’s four-seat, 200-horsepower, single-engine Taurus G4. The G4 made big news in 2011 when it won NASA’s Green Flight Challenge—a test to see if an airplane could fly 200 nm using one-half gallon of fuel (or its electrical equivalent) per passenger. The Pipistrel team—one of 14 in the running—took home $1.35 million in prize money. The 3,245-pound airplane, which has 1,100 pounds in battery weight, went on display at the 2011 EAA AirVenture.
Other Hy4 design partners included Compact Dynamics, DLR, H2Fly, Politecnico di Milano, TU Delft, University of Maribor, and University of Ulm.