I have about 2050 TT on plane and prop, in my logs it says the propeller was dynamic balanced at 1,633 hours. What is the difference between dynamic balancing and overhauling the prop. I ask because when I have N9198S painted this winter I was going to have the prop overhauled. My log book doesn’t say it was overhauled, just balanced is this the same? Should I bother with the prop overhaul if it was balanced 400 hours ago?
Bob Steward, A&P IA
Dynamic balancing is the process of using a helicopter blade tracking device (called a Chadwick) to locate and balance, with extra washers on the spinner, any out of balance in the prop and crank.
A Prop OH is removing the prop from the engine, measuring the thickness of the blades and the width of the blades at several stations out from the hub, checking he pitch angle of both blades at several stations, and checking the overall length of the prop against the manufacturer’s Type Certificate and OH manual, followed by a grinding process that removes a small amount of metal from the surface and then smoothes any nicks or chips and re-contours the leading edge. After all the metal work is done the prop is acid etched to reduce future corrosion and primed and painted. A static balance (on a knife edge) is usually done before and during the paint process with the last coat(s) of the black on the back face being used to perfect the static balance.
There is nothing in common between a Prop OH and a dynamic balance. However after a prop OH, all previous dynamic balance weights must be removed, since they will no longer match up with the freshly OH’d prop.