Pathways to Sustainable Aviation

This chapter addresses the specific pathways to sustainable aviation in key technologies, including the challenges in regulations and certifications, public confidence, and societal acceptance. Promising energy sources, as in renewable jet fuels and batteries, will continue to be the cornerstone of sustainable aviation. Cryogenic fuels, in particular hydrogen, is very attractive in fuel cell applications to replace the gas turbine (GT)‐based auxiliary power units. The future of GT engines in commercial aviation continues to be bright. The industry is moving in the direction of higher bypass ratios in geared, variable pitch turbofan engines with advanced core. Open rotor propulsor will present new opportunities in green aviation. The future of aviation is tied to carbon‐neutral growth. Renewable drop‐in jet fuels and batteries are the new energy sources for sustainable aviation. The new sector in urban air mobility will help with the certification, regulations, and operations.