The UKRI Future Flight Vision and Roadmap set out how zero emission air travel within and between British cities could be commonplace within a decade. Project HEART (Hydrogen Electric Automated Regional Transportation) addressed this zero-emission vision by revolutionising the operation of regional aircraft networks; initially targeting the 9 to 19 passenger market, with innovations in fuel, propulsion, autonomy, connectivity, operational models, and hydrogen-electric systems. The project tested new technology; including hydrogen powered flight, single pilot operations, and encrypted satellite communications. It also realised designs for new hydrogen and airport infrastructure, Inclusive terminal design and aircraft ingress, supporting sub regional flight.
Langdon et al. (Wed,) studied this question.