Abstract: A connecting apparatus (16) for attaching a propeller or fan (14) to an engine (12) is disclosed. A connecting apparatus (16) includes a centrifugal clutch device (48) and drive and driven gears (40, 78) for reducing the speed of propeller (14) relative to engine (12). These elements are contained within a lubricant-filled housing comprised of housing (38) and spider bracket (34). Spider bracket (34) includes two pairs of vibration-dampening first and second mountings (140). First mountings (140) more stiffly resist engine vibration than second mountings (142), thereby dynamically balancing the powerplant with respect to the structural frame (20).