M-T Propellers says its 11-bladed design delivers increased thrust with “an impressive noise and sound signature.” The German propmaker says it put the turbine-like device on a Piper Cheyenne fitted with P&W PT6A-135A engines and flew it a couple of months ago. “The very promising results in static thrust, 15% increase over the standard certified 5-bladed propeller, and the jet-noise signature showed another time what could be possible in the propeller developments,” the company said in a statement. Hear that “jet-noise signature” in the company video.
It seems unlikely the prop will be offered as an STC on existing aircraft, however. “The propeller system, combined with a low RPM power supply from a turbine or an electric engine, opens new possibilities for performance, efficiency, and noise,” the company said.