Dave_Jackson said:
Eliminate the tail-rotor and you reduce noise.
Implement Stepniewski's Slowed Rotor Intermeshing configuration (ABC - Synchropter) and you really reduce noise.
Graviman said:
"Making a low noise helicopter is an art, and costs weight and performance. A slow main rotor is great, but it stalls at low speed, weighs more and doesn't autorotate as well."
Guys, this ignores one facet of human behavior. People who are prone to be POed at aviation don't have to hear the hear anything to be POed. If they can see it that's enough. My old glider club got complaints about violating the airspace over somebody's house. Of course the towplane can generate a lot of ire amongst the aviation haters, but interestingly enough it's about the same if you tow right over somebody's house or are coming back at 3000 agl and low power. They just have to see you. And, stepping out of the plank world, helicopters can operate lower altitudes and land anywhere. That makes them easier to see. So, even if somebody invents a rotorless Stepniewski rotation antigravity silent vortex generator powered helicopter, somebody is going to complain about it. I think it is how these miserable people get some of the meaning for their lives.
-- IFMU