The springs in the clutchactuator get into a little "frenzy" at flight idle on the ground and breaks the little microswitches (that can only be replaced at you guessed it RHC. So to aviod having people sit on the ground at 102% for long periods the check should be done at 75%.
PS: I would much rather fly a R22\44 than the AS 365 I'm stuck in now. when it comes down (to it) small things selfdestruct with much less ferocity.