Gabriel:

The older British engines, Bristol radials and deHavilland in-lines for example, turned "Backwards." The French also had a lot of CCW engines, for this example the Salmson radials. But in every case the engines could be made in a reverse rotaton for a special installation.

The rest of the world has taken over the Limeys and Frogs now, all standard engines turn the same way.

And,as stated in an earlier post, many twins have the right engine reversed to decrease the yaw with the left engine out. This is due to torque effects - with the top of the prop turning toward the fuse torque tries to turn the plane to the running engine, minimizing the turn tendency of the engine's thrust. Doesn't eliminate it, but it helps.

Twin flying on one, try that for fun.

Bill.

PS: My ancestry includes Limeys and Frogs, so don't fuss at me about racial "Pejoratives." wr