"H.P." wrote in message
. ..
I'm taking lessons at KHPN. We've been warned about voluntary noise
abatement procedures. Has any manufacturer contemplated or actually
installed mufflers on piston planes?

Muffler-equipped airplanes are not uncommon in Europe. They don't even look
all that aerodynamic...just a big extension to the exhaust, sticking out and
along the side of the cowl.

Pete