The Germans used to keep piles of mattresses at their CH-53 operating fields for exactly this eventuality.
On the Puma we had a "sandbag plan" on board. We were supposed to give it to groundcrew who then went off searching for sandbags to place on it. Don't think it ever came in handy though. The only time I might have had call for it, sod's law said we had no fuel left....... total loss of ALL hydraulic fluid, including the reserve can - thankfully when it went "Bang!" I was quick enough to get three greens before it all blew off. The other time they dug holes in the ground for the aerials and landed all gear up. We all watched from a safe distance. Not so easy to dig on board ship though.