[hharney]

I have 3 blade MT's on my 337C. It has some reduction of sound in the cabin, 2 - 3 decibel decrease, so it must be a little quieter outside. Although my observations by way of video fly-bys does not appear to reflect a noticeable decrease in sound. It does sound different but not necessarily quieter. I would have to venture to guess that a Super Skyrocket with the larger engines even though it has 3 blade Hartzell’s, is going to be louder yet. Just my 3 cents worth.

There are a couple of 337 drivers that have been on the ground while I passed by so maybe they have a different opinion.