The article discusses the significance of electric aviation in mitigating greenhouse gas emissions from the aviation industry. It emphasizes the need for electric propulsion to reduce CO2 emissions and mentions the challenges faced in implementing electric aviation, such as technical, regulatory, and infrastructure obstacles. The piece highlights the importance of exploring alternative power generation methods for electric aircraft, focusing on the use of fuel cells to eliminate the limitations of current battery technology and charging infrastructure. The CLEAN project, sponsored by NASA and led by a U.S.-based team in collaboration with various institutions, is introduced as an initiative to revolutionize electric aviation. This project investigates the feasibility of large electric airplanes powered by liquid hydrogen and fuel cells, particularly by utilizing ammonia as fuel due to its operational advantages over liquid hydrogen. The article delves into the details of the proposed hybrid electric propulsion system that combines a gas turbine with a solid oxide fuel cell (SOFC) to enhance thermal efficiency and overall performance in generating electrical energy for aircraft propulsion. Preliminary simulations of the SOFC-GT hybrid system have demonstrated significant improvements in propulsion efficiency compared to current aircraft propulsion systems. Furthermore, the content explains the electrochemical reactions involved in fuel cell operation, particularly focusing on the use of ammonia as a hydrogen source. By breaking down ammonia into hydrogen and nitrogen for electricity generation, the CLEAN project aims to offer a more sustainable and efficient solution for electric aviation, addressing the challenges posed by storage and thermal control of liquid hydrogen.