Why do most single propellers have a clockwise rotation? Why do most single propellers have a clockwise rotation (seen from the pilot's point of view)?



There are though multi-engine planes that have each propeller rotating different directions, but in the case of single propellers, it seems that clockwise rotation is dominant, or even the only option. Is there any single propeller plane with counterclockwise rotation?
I wasn't able to find any good historical references, so this answer is pure opinion.  (sorry).  I'll break this down into two separate questions.


Is there any reason for single-engine propellers to turn the same way?


Yes.  When flying, the spin direction of the prop has several effects.  Helical prop wash, p-factor, gyroscopic precession, differing blade angles of attack all are due to the asymmetry of spinning in a single direction.  An experienced pilot will want to understand and compensate for these effects when necessary.  It is easy to see that once this is understood, a single configuration will be preferred within a community to minimize differences between aircraft.


Is there any reason to prefer CW rotation over CCW as a convention in a single engine plane?


None that I am aware of.  It appears to be simply an accident of choice.  I had wondered if the majority of engines available to early manufacturers was in that direction and made it preferable, but I couldn't find anything suggesting that.  Indeed today the majority of automobile engines rotate the opposite direction.  Making (piston) engines rotate the other direction is not a huge problem.  Twin-engined aircraft and watercraft often have counterrotating engines and propellers.