The world's first seven-bladed Unducted Prop FAN MT-Propeller has received EASA STC on Pilatus PC-12s powered by the Pratt & Whitney PT6A-67B or PT6A-67P turbine.
MT-Propeller started to develop the seven-bladed propeller in 2016, hoping to replicate the success it found back in 1999 with the first five-blade prop. The five-bladed prop has become an industrial standard, with more than 2,500 propellers sold for various kinds of turboprops. The FAA STC for the seven-blade is in progress.
MT-Propeller Vice President Martin Albrecht says that the installation of seven-bladed MT-Propeller on the propeller turbine driven aircraft PC-12 requires no engine modifications, certified ground roll distance is reduced by approximately 10 per cent, certified take-off distance over 50 ft obstacle is reduced by approximately 15 per cent, climb performance improves, aircraft noise level is about 4 dB(A) less than with the original metal propeller, cabin noise is reduced by six to seven dB(A) depending on location, and the new prop complies with the strict German noise regulations 2010 for unrestricted airport operations in Germany and other European countries.
Due to the smaller diameter, the seven-bladed MT-Propeller for the Pilatus PC-12 has more ground clearance for less blade tip erosion and FODs. MT-Propeller natural composite blades provide significant inside and outside noise reduction. They have no life limitation and are repairable in case of an FOD. They also provide good vibration damping and have bonded on nickel alloy leading edges for superior erosion protection of the blades.