Max Speed
ShyTorque (sorry about the sky..)
I am not saying they got it wrong. I am just saying that very many parameters come into play. Hitting once in a while 140, while flying most of the time 115 will be better than flying 130 all the time.. But that would be difficult and dangerous to put in the manual wouldn't it. After all fatigue comes from a overall mix in usage and pre-scribing a mix is difficult.
From practical experience I can see 10-15 knts difference between well balanced/paired and super clean blades as opposed to not so well balanced/paired/clean blades. So that would enter my personal limitations : if the thing is not well balanced I would not fly 130, let alone faster and by the way you would certainly feel it.
Now some results (be it on the edge of the precision, because I think in this regime aero-elasticity starts playing a big role (and would push stall further than in my calculations.
The most significant curve is the so-called 8-curve where for one full rotation the angle of attack is plotted versus mach and compaired to the stall curve (with prandle like correction)
1. Average weight R44-I at VNE :
2. Heavier : less margin:
3. Going to fast, in descent : still OK according to the sim (NOT ADVOCATING TO DO THIS!):
4. 5% lower MR rpm : BIG difference, so if by over powering the engine, RPM would drop off then you are in bad shape. This for me the big difference between R44-I and II in fast/high : The R44-I runs out of steam and well with the envelop limits the RPM can drop off what is dangerous):
d3