In "Shawn" writes:


Why would you want to stop the prop rotating?

First, to avoid the unnecessary wear in the bearings and sealings.

Secondly some gearboxes are properly lubricated only when they are
driven by the engine and hours and hours of propshaft rotating will
cause damage to them.

Third the resistance of the rotating prop is bigger than the resistance
of a feathered prop. This topic has been discussed here for ages, and no
unanimous agreement has been reached, because it depends on the pitch
and aspect ratio of the propeller and various other factors. The
discussion is mainly been around the fixed type propeller.

Fourth some props will make some noice while rotating "freely".

So here for starters, there might be more...

- Lauri Tarkkonen