Sharrow MX-1: Tipless propeller (2020)
It would be really interesting to see what his attempts with aircraft amounted to. Propeller tip induced turbulence is a non-trivial portion of what makes general aviation (GA) very loud. If we could make the aircraft less loud without significantly reducing their performance perhaps GA would be more amenable (along with other changes like moving eventually to electric power plants). As it stands right now the general public isn't much of a fan of GA and there is always strong push-back to creation of GA airfields which I think is a shame. The joy of flying shouldn't be limited to commercial pilots and yet increasingly here in Australia that is the way it is.Things are very different in the US because their GA culture is older, more powerful and protected by the FAA and pilots associations.