A Smooth Ride

The benefits of having your prop balanced are more than just a smooth-running engine. Prop balancing plays a significant role in decreasing pilot and passenger fatigue and can reduce the maintenance costs of wear and tear on your engine components ranging from your engine mounts and baffling to cowling and other aircraft accessories.

Balancing typically takes about an hour per engine. It is performed by attaching a photo-electric sensor with a highly accurate digital accelerometer then running the engine at the normal cruise settings. Then, weights are added to the spinner or flywheel in specific locations and the engine is run again to confirm. Usually one run is enough to get a significant improvement but, occasionally, the weights are modified slightly based on data collected from the first run in order to get a close to perfectly balanced prop. After the balance is complete you will be supplied with a report of information on how things improved, and a complete vibration analysis that can be used as an aid to troubleshoot problems with the rotating components before they fail, or can be compared to past reports as part of a trend monitoring program.

Typically, engines that have not been balanced have a starting value of between 0.25-0.60 IPS (inches per second) and after balancing we usually aim for a value of under .07 IPS.  Anything above .20 is considered “rough” and should be balanced.

Balancing is recommended by both Hartzell and McCally as well as most Reciprocating and Turbine engine manufacturers, and at a flat rate of $375 it’s cheap insurance to help get the most out of your aircraft.