I remember the Soviets converted a plane for hydrogen combustion: https://en.wikipedia.org/wiki/Tupolev_Tu-155 https://en.wikipedia.org/wiki/Tupolev_Tu-155 But

I remember the Soviets converted a plane for hydrogen combustion: https://en.wikipedia.org/wiki/Tupolev_Tu-155 https://en.wikipedia.org/wiki/Tupolev_Tu-155 But I feel that's a bit of a distraction - turbines must use thermodynamic cycles to convert fuel into thrust - something whose maximum efficiency is less than the real world efficiency of a hydrogen fuel cell. I feel like hydrogen turbofans are not practical for small craft for a number of reasons - cost, maintenance, noise, limited start/stop cycles etc., while electrics have the ability to scale to every aircraft category.