Alaka'i Technologies' Skai machine has a range of up to four hours/400 mi (640 km) and a five-passenger capacity.

Hydrogen is a difficult fuel to deal with in an automotive context, but it might just be the shot in the arm that the electric aviation industry needs to get VTOL multicopter air taxis up and running. Current lithium battery technology offers poor energy density, which severely limits the range figures of current e-VTOL projects. But hydrogen offers up to 10 times the energy density, as well as gasoline-quick refueling, if you can deal with the inefficiencies of producing, transporting and storing it. And those difficulties can be better managed in a centralized aviation model that doesn't need to roll out across the entire road network.

Thus, Massachusetts-based Alaka'i Technologies has spent the last four years beavering away at building a hydrogen-powered air taxi, which it launched today in California. According to an interview with SoCalTech, the company is operating under the funding of a sole investor, who has carried it through design, development, prototyping and is now footing the bill for FAA certification, which Alaka'i CEO Steve Hanvey says he believes should be possible before the end of 2020 due to the simplicity of the airframe.