RE: Ground Resonance!!..watch this video for sure!!!
As stated above this is dependent on the M/R design. Anything with a fully articulated rotor head can get into ground resonance. Your OH-58D has 4 blades spaced out at 90 Degree intervals. Change just one blade to about a 80 degree/100 degree interval and you have an off balanced head. You would know your system better then I but I'm sure you'd feel it and have a problem. Most times, ground resonance is encountered when you set your aircraft down on the ground and the impact of the wheel/skid can cause a blade rotation independent of the main rotor.
They tell you to come to a hover to get out of ground resonance. Good plan, but impossible when your 47 is chained down to the pad with now where to go.
Happy Hooking