At a somewhat small and unassuming airport in Maribor, Slovenia, German hydrogen propulsion startup H2FLY has quietly been building up to a major milestone in zero-emission aviation over the summer. And all the hard work has come to fruitio
World’s first crewed liquid hydrogen plane takes off::undefined
LEL for Hydrogen: 4.0 (% in air)
UEL is 75 %
This is the most severe (wide range) for any fuel.
LEL and UEL Explained (Explosive Gas) - Projectmaterials
This is on top to hydrogen enbrittlement and low temperature enbrittlement of metals.
Good luck with the insurance fees for commercial flights.