An awesome idea from Spain: hybrid airplane powerplant. Airplanes need about 65 percent power for a reasonable cruise. Airplanes can certainly fly on 35 percent power. Thus having an electric motor that can be used for a boost on take-off and as a backup in case the reciprocating contraption comes apart comes with potential weight savings as well as some potential safety improvements (though not too many accidents are caused by power failure).
With typical regulatory certification challenges this might be ready in 10 years!