I find this area of engineering to be intriguing, to say the least. A company called "Sirius" has developed two different hydrogen-fueled aircraft that is going through testing and will debut next year. It will be the first zero-emission jet with long range capability. For now, it is only "Business Jet" size, but larger sizes are planned. It has vertical takeoff and landing capabilities like a helicopter. This area of technology is fascinating...to me anyway. I really hope hydrogen is the future of energy propulsion. I have too much money wrapped up in hydrogen companies' stock while betting on it.
https://www.hydrogeninsight.com/transport/formula-1-engineering-swiss-start-up-unveils-futuristic-hydrogen-powered-passenger-aircraft/2-1-1582110
https://www.hydrogeninsight.com/transport/formula-1-engineering-swiss-start-up-unveils-futuristic-hydrogen-powered-passenger-aircraft/2-1-1582110