When landing, helicopters don't sit on the ground properly, and push themselves in the ground when the throttle lets the heli drift down.

Do those skids have "suspension" on them? The blue wheel boxes look like they're moving... Also, what's the pitch of that rotor?

Closing as this is more related to #1339 than bad ground physics. The rotor is not happy, that needs to get fixed, not the skids.