The idea for synthetic fuels is that they can act as a drop-in replacement for fossil fules, so you don't have to adapt the vehicles. I wouldn´t call using H2 a

The idea for synthetic fuels is that they can act as a drop-in replacement for fossil fules, so you don't have to adapt the vehicles. I wouldn´t call using H2 a synthetic fuel, because it would require a different aircraft design (its probably more reasonable appraoch overall, although access to truly carbon free h2 is limited right now).