Negative pitch would work to regain rotor speed in case of a botched autorotation. The problem is what to do if somebody selects negative pitch while under power.


Easy you say? put a lock out in the lever such that it can't go past negative if the engine is running? Really?


Robbies still kill you if you forget to pull carb heat, when an automatic carb heat actuator could easily be fitted. Why the hell would we try to save somebody who can't keep their rotor speed in the green?

The idea is that you can apply negative pitch whilst under power to make sure you stick to the surface.
That way if the surface moves you don't take a different path to it.

There will come a point, after an engine failure, where the Nr will be unrecoverable without engine power, no matter what you do with the collective.

I would suggest on a low inertia head like the Robbie, that might even be above 80% Nr

Depends on density. Hot and high IIRC it was somewhere around 87% give or take