SLB
quite funny, some of the conversation has been good , but engagement with Crab has not been productive, by his own admission he is only trying to goad me, not very helpful.
The productive elements i suggest from this are
1 the idea that coning really doesn't have the capacity to continue smoothly to very large values but rather has an approximate coning angle band (UCA) that does not get exceeded regardless of RRPM
2 Rotor heads need only accommodate a coning range, plus a suitable margin, I am sure designers do consider this, anyone confirm that?
3 Pilots should understand that the load they can pull hit a sort of brick wall beyond which pulling harder will not give greater TRT, it will just wash off energy (agressively possibly, probably with stressfull vibration) and if there is insufficient supply of energy RRPM will reduce but the coning angle won't keep increasing at that point. (despite the wrong intuitive idea that it does). It has undoubtably resulted in many of the accidents where the pilot expected to be able to pull suffieciently, but could not, sometimes due to high DA or heavy weight, or indeed reduced RRPM
4 A photograph of a helicopter showing a 10deg coning angle can tell you it was at limiting load, regardless of whether the RRPM had drooped or not. if 3degrees is normal cone and the helicopter can pull only 3g in that condition (at normal RRPM) then it'll reach it's limit thrust at 9deg cone, regardless of the RRPM (although obviously that will not represent 3g at the lower RRPM, it'll still be essentially the same Cone Angle UCA (this is subject to some small second degree variations for actual circumstances (like the reduction in Ct/sigma with Speed, and to some small extent the subtle variation for different induced flow conditions))
Beyond that it is only interesting as a curiosity of understanding.
I don't hold out that it should be an instrument for the pilot, but it might be interesting.
It might for instance show you a Thrust Reserve (equivalent) for different weights and DAs for instance. FWIW
(Crab I don't think the BERP blade will make significant difference to the essential quality of this observation since the first order variables are still the same. I wish you'd try and understand it since i think you'd like the idea if you could see beyond trying to diss me!)