Propane always struck me as a potential lower carbon aviation fuel since it easily liquifies under modest pressure, making the whole system lighter and more com

Propane always struck me as a potential lower carbon aviation fuel since it easily liquifies under modest pressure, making the whole system lighter and more compact than natural gas or hydrogen. Batteries would AFAIK need a 2-4X power/weight density improvement to do anything more than short haul electric flight. Short haul electric planes are possible today but not beyond a few hundred miles range.