Will the Piaggio Avanti Shed Its Distinctive Whine?
According to an industry source, Piaggio will announce more improvements for the P.180 Avanti twin turboprop before year-end. While the source wouldn’t discuss more details, one of the most obvious areas that Piaggio has yet to address is the Avanti’s unmistakable whine, which has led to its being the only modern turboprop banned under noise restrictions at Santa Monica (Calif.) Airport. Because Avanti noise is generated by its propellers, any efforts to lower the noise footprint will likely involve changes to its Hartzell HC-E5Ns props. The current blades are aluminum, but the FAA type certificate data sheet shows two other allowable materials: aramid (Kevlar) and carbon composite. Because exhaust gases move aft through the propellers on the Avanti, carbon composites cannot be used since their melting point is 400 degrees C. However, aramid materials can withstand the same 500 degrees C as the aluminum blades, possibly making them a viable replacement if resins that can withstand high temperatures are available. The aluminum props are limited to a maximum of 850 hp at a maximum 2200 rpm, while the aramid blades can handle 1,645 hp and 2000 rpm, meaning aramid could deliver the same or better performance and less noise at a lower rpm. Piaggio America said it is “always looking for ways to improve the specs and performance of our aircraft…[but] we have no immediate plans to make a change by year-end.”