Would a few splashes realy hurt a plane goin' 300+mph in one direction, i can see it maby knocking it off flight path a WEE bit, but..far be it from knocking a engine out, or riping a wing off.
Maby to blind them, but thats about it as the prop would make quick work out of water splashed up from a few hundred rounds.
:Edit" not to say it would survive a huge splash from a cv round, or the ju's huge cannons "i remember it having like 60 foot tall water spouts, big thick ones too.
And how low would a ac need to be to be greatly effected.