"Unloading a prop"
I am not sure as to what it means to 'unload' or 'load' a prop, so first let's start with the basics.
When one selects a prop, there are always two numbers to look at.... For instance, in my OS .40 FX engine, I would use a 10x6 prop as per recommendation by the company. The 10, represents the propeller diameter (right?) and the 6 represents (what?). Does the 6 have to do with the angle of attack (or pitch) of the blades?
....Ok, back to the original question of loading and unloading. I know that in order to provide thrust for the airplane there are two main ways this can be accomplished. (1) We can use a small prop and accelerate a small mass of air to a very high velocity. Conversely, we can (2) accelerate a large mass of air to a slower velocity using a much larger prop.
Does this have anything to do with loading and unloading the prop?
Many thanks,