P.180 reasons for having pusher propellers
"Pusher propellers were chosen to allow an undisturbed airflow over the wing so as to contribute to maintaining laminar flow over as large a portion as possible of the wing. An additional advantage is a drastic noise reduction in the passenger cabin. The aft position of the engine/propeller assembly also contributes to reestablishing the relative position of the C.G..
A side benefit of pusher propellers is that engine exhaust gases impinging on propellers blades make a blade de-icing system unnecessary."
Taken from: “PIAGGIO AERO INDUSTRIES: A LONG HISTORY OF INNOVATION”, AIAA/ICAS International Air and Space Symposium and Exposition: The Next 100 Y 14-17 July 2003, Dayton, Ohio