Sora Aviation has started a battery testing project for its planned 30-seat S-1 eVTOL aircraft. The work is being conducted in partnership with the University of Bath in its IAAPS propulsion research center at the Bristol & Bath Science Park.
The campaign involves extensive testing of high-energy-density battery cells being evaluated for use in an all-electric propulsion system. The company said it will support flights of up to 87 nm, although it expects many missions to be around 22 nm.
The powertrain will be integrated with six tilting rotors installed across a tandem wing configuration. Early drawings of the S1 model show a shorter forward wing with a rotor installed at each wing tip. The longer rear wing has four rotors, with two installed inboard and two on the wing tips.
The Sora team aims to have a full-scale technology demonstrator ready to start flight testing in 2028. It aims to achieve type certification and entry into service in 2031 with the S-1, for which the primary early use case is expected to be shuttle services to and from airports.
According to Sora, early engineering studies have established that the battery weight per passenger does not need to increase for an electric aircraft with more seats since the energy consumption is proportional to takeoff weight. On this basis, the company believes it can deliver a seven-fold increase in passenger capacity with similar battery weight per person as other eVTOL aircraft, and with fares at around a quarter of the cost of air taxi services.
The company expects to partner with specialist suppliers for key elements such as electric motors and fuselage sections while using its own designs for systems such as the tilting rotors. In the longer term, it may subsequently consider alternative powertrains such as hydrogen-electric and diesel-based hybrids for possible military applications.
“At IAAPS, we thrive on working with forward-thinking companies like Sora Aviation, whose vision for advanced air mobility aligns with our drive for technological innovation,” said Chris Brace, executive director of IAAPS. “This battery testing project is a pivotal step toward realizing the potential of electric aviation, and our partnership reflects our shared dedication to pioneering energy solutions.”