The companies signed the partnership at Bern Airport, where H55’s certified aviation batteries were confirmed as the core system for Smartflyer’s SF-1.

Projections suggest eventually $180bn dollars will be poured into battery and hydrogen aviation technology but to date $15bn has been spent developing Sustainable Aviation Fuel.

With its rear propeller and modular nose, the SF1 will fly silently like a glider and cover longer distances, and will go from electric to hybrid combustion engine in 15 minutes. The prototype was unveiled at Grenchen airport.