IIRC the Westland Wasp, designed to operate off small navy ships, had negative pitch to make sure it stuck to the deck when it landed despite whatever pitch and roll the ship could throw at it.
The Lynx, it's replacement, had a harpoon system the hooked onto a grid so as to do the same thing.
I would only work with a fairly rigid rotor. Big wavy blades on a larger machine would probably strike the boom.
You can always ask yourself why they fit droop stops to rotor heads.
Last edited by Fareastdriver; 28th Feb 2016 at 13:05.