FAQ 
· Even under the most ideal conditions, at best, a propeller is 85% efficient at converting torque to thrust.
· And you thought you were stressed out!!!   The amount of stress created by centrifugal force upon the propeller hub, while prop is in max RPM, may be greater than 7,500 times the weight of the propeller blade. Or, 10-25 Tons exerted on the hub!
· Red Dye leakage from any part of your propeller is very serious and should be looked at immediately! This pertains to McCauley “oil filled” propellers.
· Unseen corrosion is one of the most common causes of part rejection/failure of propeller components.
· The internal components of propellers are subject to wear, and can only be inspected after full disassembly. *Note= Only certified propeller repair stations are authorized to do such work.
· While running up engines for an oil change, it is recommended to fully feather propeller to help flush out sludge which accumulates inside dome. Full feathering propellers are found on twin engine aircraft and some single engine turbine aircraft.
· If the manufacturer recommended overhaul times are not adhered to (part 91 operations), H&S Propeller strongly recommends a 5 year grease and/or reseal service.
· Abnormal grease leakage or vibration can be an indication of a failing propeller or blade retention component. An in-flight blade separation can result in a catastrophic aircraft accident!
· McCauley propellers are not field serviceable. Once the propeller had been repaired/overhauled, the lubricating grease cannot be replenished.  The total amount of grease in these propellers is NO MORE THAN A TABLESPOON!!!  So any noticeable grease leakage is not good.
· Blade separation starts with stress concentrated in a very small area. Any nick in a blade that is greater than 1/32” wide should be dressed out by an A&P Mechanic prior to the next flight.
· Most governors require a mandatory overhaul when there has been a foreign object strike or metal contamination.

 * It is recommended that during ground run checks that a maximum of 300 RPM drop be allowed during the cycling of the propeller. Excessive drop in RPM is hard on propeller and other internal engine components.