My layman's aerodynamic hunch says that Lilium is on the right design track for practical, reliable, long-range electric VTOL aircraft. There's two critical in

My layman's aerodynamic hunch says that Lilium is on the right design track for practical, reliable, long-range electric VTOL aircraft. There's two critical ingredients: Transitioning out of powered lift immediately after takeoff, and having a battery mass fraction that's as high as possible. Obviously, VTOL & payload limits the latter. Multicopter designs won't work; their power requirements are too high.