[SigmundA]

Seems like this would be a step backward in efficiency. Direct mechanical drive is more efficient than double conversion at cruise speeds. Even the Gen1 volt connected engine to wheels at highway speed because it was more efficient, Gen2 they went to a more conventional hybrid design like a Prius with mechanical power splitting because its more efficient even at lower speeds.

Airplanes are even simpler using variable pitch props the ICE just runs at it most efficient rpm with no or minimal transmission and nearly zero mechanical losses.

Also a hybrid design is heavier than a direct mechanical and airplanes would seem to not benefit from hybrid advantages such as regenerative braking and 0 rpm torque.