Originally Posted by
Rob2160
But the water in liquid form doesn't damage the engine therefore the hardness does make a difference. Which was the whole point of our discussion.
Water is not solid and thus has no hardness nor form, hail is solid and very large hail will do damage to the engine. I never said hardness doesn't matter, just that electric motors (of small sUAV) are not hard enough nor large enough to do enough damage to stop the engine.