Presumably tied to the fact that Obama is in London at the moment, I just had a V-22 fly over my building in East London. It was in helicopter mode, IE rotors were horizontal, and I was surprised at just how loud it was.
I’ve heard plenty of helicopters before, which is why I was surprised at just how loud the V22 was. Presumably it’s the double rotors that cause it? I’ve never heard a Chinook before to compare.
My last job was on NAS Patuxent River where they do flight testing of the V-22. Our building was literally right next to the taxiway and there were 2 Ospreys in the hangar a few hundred yards from us. When those suckers were operating, our whole building shook!
Yep, they’re loud!
Smaller rotors than a conventional helicopter spinning faster make more noise, also the exhaust from the engines is directed down, so again more noise; I would guess a flyby in horizontal flight configuration would be much more quiet, for certain values of quietness of course.