I feel there is an unaddressed market for a hybrid gas/electric or diesel/electric powerplant.
Size the battery for takeoff/climbing/go-around/diversion use-cases. Size the fossil-fuel engine for cruising power, which should improve efficiency. During takeoff and climbing power, the two motors work together. During cruise and descent, the electric motor regenerates the battery. I imagine that for general aviation, you would maintain one propshaft and not even bother with a clutch pack, since the gas engine is needed in all phases of flight, and freewheeling an electric motor is simple. Perhaps have the fossil-fuel engine keyed to the shaft with a shearing pin, so that if the engine seizes, the electric motor still turns the prop.
This has the advantage that you now have two independent motors, which could eventually help with ETOPS rating, but would initially improve safety/reliability for general aviation.
Yes, you are still fossil-fuel dependent, but you burn much less of it, first by offsetting some takeoff energy to the electrical grid, and secondly by reducing reserve power in the fossil fuel engine to improve efficiency.
Size the battery for takeoff/climbing/go-around/diversion use-cases. Size the fossil-fuel engine for cruising power, which should improve efficiency. During takeoff and climbing power, the two motors work together. During cruise and descent, the electric motor regenerates the battery. I imagine that for general aviation, you would maintain one propshaft and not even bother with a clutch pack, since the gas engine is needed in all phases of flight, and freewheeling an electric motor is simple. Perhaps have the fossil-fuel engine keyed to the shaft with a shearing pin, so that if the engine seizes, the electric motor still turns the prop.
This has the advantage that you now have two independent motors, which could eventually help with ETOPS rating, but would initially improve safety/reliability for general aviation.
Yes, you are still fossil-fuel dependent, but you burn much less of it, first by offsetting some takeoff energy to the electrical grid, and secondly by reducing reserve power in the fossil fuel engine to improve efficiency.