Having said all that, any helicopter pilot with common sense and consideration would be careful not to allow his downwash near a light aircraft (or another helicopter), if ground taxying (or waiting for a minute) would prevent it.
Unlike one Squirrel pilot I had words with recently, having watched him stupidly hover taxy over the starboard wing of a running Cessna 152 because it was blocking his way in to dispersal! He claimed it to be an ATC problem...
If he had waited one minute, off to one side, the Cessna could have taxied out and gone clear. His downwind, high hover taxy departure from dispersal, probably in the avoid curve, looked no better, mind...
