RFDS Turboprop Fleet Change To 5-Bladed Composite Blades The Royal Flying Doctor Service (RFDS) is presently engaged in changing the blades on all of their Pilatus PC-12 turboprops. The original four-bladed Hartzell props are being changed for new Hartzell five-bladed composite blades. Why is there a concerted move to do this? Down the road the new blades are expected to bring cost savings to the operation of the Pilatus fleet in the RFDS. The blades are higher performing as well and even provide more comfort to patients onboard as a result of less vibration.